Steam-cleaning Put a microwave-safe dish of water in it and cook on high for 3-4 minutes. The steam will loosen any baked-on crud. I use a mixture of 1/3 each lemon juice, white vinegar and water in a spray bottle as an all-purpose kitchen cleaner, so after boiling the water, I'd spray the inside and outside of the micro with my cleaner and wipe it down good. Use a soft green scrubbie if you need to.
I do the same thing. If it's just crud, I use plain water. But if it was exploding pasta sauce or something else with a strong odor, I add the lemon or the vinegar.