How to clean the interior of a microwave?
My sister burned some plastic in her microwave. It has a typical off-white painted, enameled?, metal interior, and it's gotten surprisingly dirty. Spray cleaners don't do much, I guess because they are meant for grease. (I cleaned the glass tray with a razor-blade scraper, but even with that, it was hard to get everything off.)
Soft-scrub products and iirc Bon-Ami use calcium-carbonate, which has a Moh hardness of 3. While I've used but never visibly scratched anything with either of those products, I don't think I've used them on painted surfaces. Especially in a hard to reach inside, normally just wiped microwave, scratches will pick up dirt and look terrible (if I bend over!). Even the Soft-scrub surface guide doesn't seem to recommend this**.
Talc has a hardness of 1. I have some of that, and some baby powder, somewhere and plan to try it, but ....
I see that gypsum has a Moh rating of 2. Can I make some cleanser out of a piece of sheet-rock? Pound it down to dust (wearing a respirator?), add a little water, and some kind of thickener??? This is a lot of work for one microwave, but it may be useful many other places. Maybe I could market it and get rich. OTOH, there are people who do nothing all day but work on new cleansers, and this is pretty obvious, so they must have tried this already. Still, maybe it is better for this particular purpose but not marketable enough that they produce it.
A) How should I make gypsum-based cleanser? B) What do you think of the whole idea? C) Do they already sell this and I've missed it? D) Comments?
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