The tip on the website seemed brilliant:
put damp sponge in the microwave for 3-5 minutes every night to sanitize it.
So, Monday night, I tried it.
I will not be doing that every night.
In fact- I will never do that again unless I want a burnt sponge, a house full of plastic scented smoke (that is still lingering three days later) and an evening of frustration (not to mention a headache from the stench).
Epic fail.
(Come to find out this is epic fail #2 of the same brand. I did not think it was possible to have two epic fails of the same nature, but my mom assures me I tried this several years ago and the same thing happened. You would think one would remember the smell and never attempt sponge sanitation via microwave ever again.)