When to change your kitchen sponges

[misbegotten]

I've seen a number of conflicting reports on how often you should change your sponges and, particularly, whether microwaving a sponge will disinfect it. Lifehacker examined the data and concluded that microwaving a sponge can kill a lot of bacteria but they still recommend replacing sponges once a month.

From the same article:

How to microwave your sponge:

1) Make sure it doesn't have a metallic scrub pad. Those should be cleaned in your dishwasher on high heat, including a heated dry cycle.

2) Get it completely wet. Dry sponges can catch fire in the microwave.

3) Zap it on full power for one minute.

4) Let it sit in microwave for five to ten minutes to cool down before removing.