Here’s an article that likely shares its source with the radio report you heard. The takeaway is that cleaning a sponge by microwaving or dishwashing it is worse than ineffectual, it’s actually “similar to how people can encourage antibiotic resistant bacteria if they don’t follow the doctor’s orders” by taking their full course of medication. Except that that particular theory doesn’t hold water, according to this.
So! I don’t know what the hell to believe. Still not planning on replacing my kitchen sponge every week, though.
