Kitchen sponges have billions of bacteria, including kinds that make humans sick. Sterilizing them with hot water or in the microwave does not work and can even make it worse. Authors recommend getting a new sponge weekly.

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Kitchen sponges have billions of bacteria, including kinds that make humans sick. Sterilizing them with hot water or in the microwave does not work and can even make it worse. Authors recommend getting a new sponge weekly.