Sponges allow easy cleanups for kitchen and bathroom spills, but are notorious for harboring harmful bacteria if they are not properly sanitized and dried out. A wet sponge is a breeding ground for bacteria and easily becomes the source of germs rather than preventing them if left untreated. Throw sponges out once they have a sour smell or if they begin to look dingy to protect your home and yourself from germs, according to Good Housekeeping.

Step 1
Fill the medium-sized bowl with 1 gallon of warm water and pour 3/4 cup bleach into the bowl.
Step 2
Submerge the sponge into the mixture for five minutes.
Step 3
Remove the sponge from the bowl and place it in the microwave. Set the microwave to one minute for scrubbing sponges or two minutes for cellulose sponges.
Step 4
Press "Start" on the microwave and remove the sponge after the microwave timer goes off.