A dirty sponge is one of the germiest things in your kitchen, and it’s easy to forget how gross they get with that sponge smell, that's why I'm not a sponge person. And whether it’s scrubbing dirty dishes or wiping counters, it's picking up a certain percent of bacteria along the way. But not every type of sponge or cloth can be cleaned the same way, and because of health risks, some aren’t worth saving.

Why Kitchen Sponges Get So Gross So Fast

Sponges are warm, wet, and full of food particles. Every time you wipe a dish or a countertop, you're not just cleaning; you’re also collecting food debris and millions of bacteria. And when sponges stay damp between uses, they turn into a breeding ground.

Raw meat is especially risky. If your sponge touches juice from raw chicken or beef, it’s better to toss it. There’s no reliable way to fully disinfect a sponge that’s soaked up juices from meats. It’s not just about removing visible dirt at that point—it’s about getting rid of dangerous bacteria.

“Cleaning” and “sanitizing” are not the same thing, explains Mary Gagliardi (aka “Dr. Laundry”), Clorox's in-house scientist and cleaning expert. She goes on to provide lots of insight when it comes to a healthy kitchen and safety at home. “Cleaning is a physical process that removes dirt and soils and some microorganisms from surfaces; cleaning products can help improve this process.” But if you want to go further and actually reduce bacteria to safer levels, you’d need to sanitize it. And there’s a catch.

“The EPA has no approved test method for sanitizing sponges,” notes Dr. Laundry. “Sponges are not hard surfaces or textiles, so they don’t fit neatly into existing testing protocols to establish sanitizing efficacy.” That means even the strongest cleaners can’t officially claim to sanitize your sponge.

How to Clean (and Try to Disinfect) Kitchen Sponges

You can’t truly “sanitize” a sponge the way you would a countertop; however, you can clean them often and reduce bacteria.

• Microwave Method: Wet the sponge first (very important, so it doesn’t catch fire), then microwave sponge on high for one minute. This can kill some harmful bacteria. According to the USDA, microwaving your sponges may help to reduce bacteria. But it doesn’t make the sponge germ-free.
• Dishwasher Method: Place the sponge in the top rack and run it through the hottest cycle with a heated dry. This cleaning method won’t kill every germ, but it can reduce bacteria and clean off grime. Do this daily if you use the sponge a lot.
• Bleach Soak (for dishcloths, not sponges): Sponges don’t have an EPA-approved method for sanitizing, but dishcloths do. As Dr. Laundry recommends: “Add 2 teaspoons Clorox® Disinfecting Bleach to 1 gallon of water. Soak the dishcloths for 2 minutes, then rinse and hang to dry.”
• Boiling Water: Much like the microwave method. Putting your sponge in boiling soapy water can kill some harmful bacteria, but it's not 100% and we can't condone it for getting a sponge clean. But if you try it, careful with the hot sponge.

Try not to use the same sponge for everything. Have one for dishes and another for counters. And if you’re cleaning up after raw meat, don’t risk it—throw it out.

How Often Should You Clean or Replace Sponges and Cloths?

If you’re using your sponge daily, clean it at least once a day using the microwave or dishwasher method. For heavy use (like cooking for a large household), you might need to clean it more than once.

Even with daily cleaning, a sponge should be tossed every one to two weeks. It’s just not worth keeping around when it starts to smell due to bacterial growth, change color, or break apart.

For dishcloths, wash them every day or two in the laundry, or soak them in a bleach solution. These can last longer than sponges, but only if they’re cleaned often.

Here are some signs it's time to get rid of your sponge or dishcloth:

• It smells, even after you clean it
• It’s slimy or has visible stains
• It’s falling apart or losing shape
• It touched raw meat or raw egg

What About Other Sponge Types Like Swedish Cloths, Norwegian Sponges, or Layered Sponges?

My favorite for cleaning counters and wiping up water. Swedish dishcloths are reusable, absorbent, and made from cellulose and cotton. You can toss them in the laundry or even the dishwasher. They dry quickly, which means fewer bacteria stick around. Wash them every two or three uses, and they can last for months.

Some newer sponges have extra scrubbing layers or are made of materials designed to dry faster. These can help reduce bacteria but still need regular cleaning. If they’re dishwasher-safe, run them through on a hot cycle. If not, hand wash with soap and hot water, squeeze out the excess, and let them dry completely between uses.

Whatever type you’re using, dryness is key. A dry sponge or cloth is less likely to grow bacteria. Don’t leave them sitting in the sink or folded in a ball—squeeze out the excess water and let them air dry flat or hang them over the faucet or sink edge.

FAQ

Can I use white vinegar to clean my sponge?

Sure, but it’s not very effective method for killing bacteria. It might help with smells, but it won’t disinfect the sponge.

Is microwaving a sponge safe?

Yes, but only if it’s a wet sponge. A dry sponge can catch fire in the microwave.

Can I sanitize a sponge with bleach?

Bleach kills germs, but sponges aren't approved by the EPA for sanitizing claims. That means we can’t say for sure how effective it is on sponges. It’s better used for dishcloths, which do have approved methods for sanitizing.