[visualops]

Those sponges are crap.

Besides, if you can clean it, why throw it away?
OTOH, I wouldn't waste electricity nuking it, I clean sponges in a mild bleach solution.

[zerosix]

I, too, used to bleach mine but my daughter said, "Hey Mom, you don't need to waste time soaking in bleach solution, I just put mine in the dish washer and run it with the dishes."

Yet another way to clean sponges.