You can’t remember where you heard it, but someone once told you that zapping your sponge in the microwave was a good way to kill off harmful bacteria.
According to a new study published in Scientific Reports, microwaving your sponge actually does the opposite: It leaves your sponge even more bacteria-filled.
Here’s why: Apparently, the heat only kills some of the germs, leaving the worst-smelling and most pathogenic strains of bacteria behind. Even worse, other methods (like boiling it on the stove or tossing it in the dishwasher) are just as bad, enabling the most dangerous types of bacteria to “colonize” on your sponge. Ew.
The solution? Replace your sponges for the love of Pete—as frequently as once a week. At 50 cents a pop, it’s a small price to pay for your health.