JACKSONVILLE, Fla. – For years we’ve heard you can sanitize your sponge by putting it in the microwave or boiling it in water. But according to the results of a study published in Scientific Reports, neither method makes your sponge completely germ-free.

In fact, researchers said they found two types of bacteria were more prominent on these sanitized sponges than on unwashed ones. This is why they suggest the best way to know for sure is to replace your sponge every week.

If that is just not an option for your budget, Real Simple magazine suggests you can soak your sponge in vinegar for 5-10 minutes. Vinegar does sanitize, but keep in mind it does not kill all the microbes that may be growing on it.

One sign it is time to throw out your sponge right away is if it smells. The odor is a sign bacteria could be brewing.

To get more life out of your sponge and to avoid cross-contamination, you should have one “bad sponge” in the kitchen, this is the one used to wipe raw meat, and a good sponge. Be careful not to stack them together since that could lead to contamination of the good sponge.