The best way I’ve found to clean my microwave is to take a rag, wet it, and ring it out—but not tightly. I place it in the microwave and set it to 25 seconds. When I open the microwave, the rag is hot enough to remove any buildup but not so hot that I can’t hold it.
I use this to wipe out the microwave and it works every time in a matter of minutes. I got the idea from those expensive microwave cleaner packs that work the same way. Debbie