How often to clean everything you own, from your toilet to your phone, according to science

Your sponge is one of the grossest things you own. Microbiologists say you should replace it once a week.

The warm, moist environment inside a sponge is a delightful spot for bacteria to grow.

Microwaving or boiling sponges won't sterilize them — it'll only kill about 60% of the bacteria they're hosting. Bleaching a sponge is more effective, and a solution with 10% household bleach and 90% water solution should do the trick.

Tasting Table suggests that you can bleach a kitchen dish sponge after week one and relegate it to countertop-wiping duties, then bleach it again after week two and move it to bathroom polishing. Bleach is strong enough to kill anthrax spores, and it's always good to bleach a sponge after it comes into contact with raw meat or vegetables.

Your phone should get a daily wipe down.

Smartphones are with us nearly every waking moment. They often come into the bathroom and fall on the ground. They sit in our palms at almost every stage of the day, regardless of where our hands have been or how clean they are — and then we nestle the phones next to our ears.

It's no surprise, then, that smartphones can pick up E. coli and Streptococcus bugs along the way. A phone can easily be dirtier than a toilet seat. So most infectious disease experts, like Philip Tierno, a microbiologist and pathologist at the New York University School of Medicine, suggest giving it a wipe at the end of the day.

You can use a wet wipe or a gentle microfiber cloth. For extra cleaning power, add a 50/50 solution of water and vinegar to a corner of the cloth.

We spend around a third of our life rolling around in our sheets. Science says washing them every week is best.

Our beds are wonderful places for life to thrive. Skin cells, lotions, powders, and oils on our skin, as well as little crumbs of food, all contribute to a germy, microbial soup of growing filth that we sleep with every night.

Change your sheets once a week to keep the dirt levels in check, as Tierno suggests.

The toilet gets an unfair reputation, but microbiologists say the seat is one of the cleanest places in your home. Clean it once a week.

Our toilets are far from the dirtiest thing we touch. According to microbiologist Chuck Gerba, they have around 50 bacteria per square inch on the seat.

"It's our gold standard — there are not many things cleaner than a toilet seat when it comes to germs," Gerba told the BBC.

Things like restaurant menus, steering wheels, and even computer keyboards can be much dirtier. Still, Gerba says that's no reason to skimp on bathroom cleaning. Cleaning experts agree it's good to give the "throne" in your home a good wipe-down every week to keep it sparkling.

Close the lid when you flush to keep any dreaded plumes of particles from whooshing up into the air.

While you're in the bathroom cleaning the toilet, spiff up the rest of the bathroom about once a week, too.

It's best to scrub your sink, empty the drains, and clean the walls of your shower and tub once a week, too, microbiologist Jason Tetro told NBC.

If you have a plastic shower curtain, put it in the wash every one to two weeks.

A 2004 study suggested that shower curtains can be dangerously pathogenic for people with compromised immune systems. Reader's Digest suggests sticking your shower curtain into the washing machine with a couple of towels to wash away soap scum accumulation.

"Add 1/2 cup baking soda to your detergent during the wash cycle and 1/2 cup vinegar during the rinse cycle," Readers Digest says. Then let the curtain air dry.

Towels often don't get fully dry before we use them again, making them a perfect place for moisture-loving bacteria to grow. Wash them once every three uses.

"If there is odor coming from the towel, wherever there is odor, there are microbes growing, so it should be washed," Philip Tierno, a microbiologist and pathologist at the New York University School of Medicine, previously told Business Insider.

That rule goes for kitchen dish towels too: throw them in the wash after a couple of days to avoid buildup of potentially dangerous E. Coli spores.

The kitchen sink is second only to the sponge when it comes to germs. Disinfect this basin once or twice per week, and immediately after you use it to handle raw meat.

The NSF, a public health organization, suggests using a disinfecting cleaner or a tablespoon of bleach in a gallon of water to scrub out the sides and bottom of the sink. Bleach-maker Clorox suggests upping the concentration to half a cup of bleach per gallon of water.

After scrubbing with your bleach solution, wait five minutes then rinse the sink out with water and let it dry.

Despite what some denim manufacturers say, jeans need some washing to stay fit and smell-free. Suds 'em up every four to six days to stay fresh.

That jeans-in-the-freezer trick? It doesn't actually kill any bacteria lurking on your jeans, because your freezer is simply not cold enough.

So put your jeans in the wash after four to six days of wear, microbiologist Steven Craig Cary says. That will tighten up the fibers that loosen while you wear the pants — and keep your neighbors' noses happy, too.

Unplug and deep clean your fridge every three to four months, wiping down the shelves and drawers with warm, soapy water.

That'll help keep the fridge humming along dry, cool, and microbe-free, while also preventing frost buildup in the freezer. The USDA suggests doing a deep clean of your fridge "several" times a year, including dusting off the coils on the back, to keep it running efficiently.

Dust, sweep, and wet-wipe or mop once or twice a week, depending on how busy and hairy your house is.

Microbiologist Jason Tetro, author of "The Germ Code," says you'll probably want to sweep up more often in places like the kitchen, where food crumbs are everywhere.

Dog experts say a monthly bath is the best way to keep your pooch healthy.

You may want to hop in the shower a little more often than this yourself, of course. But most dogs should never be washed more than once a week, according to dog "whisperer" Cesar Millan.

When washing your pup, dog shampoo and baby shampoo both work.

If you have carpets, vacuum once a week, or twice in high-traffic areas.

Tetro told NBC that rugs should generally be vacuumed once a week, but more often if you've got pets.

Another household item that's often dirtier than a toilet seat is your keyboard. It's good to wipe down your keyboard, mouse, and monitor every few days.

The keyboard isn't the only thing on your desk that's germy. An Australian study found that the average work desk has 400 times the amount of bacteria found on a toilet seat.

The National Center for Health Research suggests washing hands before and after using shared computers, especially during flu season.

To wipe your computer down, you can use a q-tip dipped in alcohol or a cloth with disinfectant cleaner. Always shut the computer down and unplug it before you clean it up.

The inside of a coffee pot is dark and damp, which makes it a great place for germs to grow. Clean it out once a month.

If you're cleaning a drip coffee maker here's what the NSF suggests: Add up to four cups of undiluted vinegar to the reservoir, let that sit in there for 30 minutes, then run the vinegar through the coffeemaker. Afterwards, run a couple cycles of fresh water through to get rid of any vinegar taste.

You can also use vinegar to clean a french press. Whatever device you use to caffeinate should be cleaned out once a month to keep your coffee tasting fresh.

Doorknobs can be great vessels for spreading germs quickly. Wipe the ones in your house down about once every week or two.

A germy door can spread a nasty virus around an office in mere hours. At home, make doorknob cleaning part of your regular routine. If someone at home is sick, wipe down knobs more frequently.

Your face doesn't need to be washed more than twice a day.

When it comes to cleaning your own body, you don't want to be too harsh to the protective, moisturizing lipids on your skin, since those inevitably get washed away along with oil and dirt.

Dermatologist Terrence Keaney previously told Business Insider that washing your face more than twice a day or scrubbing extra hard is mean to your skin. Plus, some of the organisms in our skin's microbiome are essential illness-fighters and fungus-raiders.

So it's important not to wash them all away.

But the most important item you're probably not washing enough? Your own hands.

Our hands are with us all the time. We use them to eat, shake hands, wipe our derrieres, and give others high-fives. So they're arguably the most important thing we own that could use more washing.

Doctors say frequent hand-cleaning is the best way to avoid getting sick. But health-care professionals could stand to take more of their own good advice — the World Health Organization estimates that hand hygiene compliance rates for health-care providers are typically well below 40%.

We'd all do a little better if we washed our hands more often.