I love steam for cleaning. I use a steam mop with plain water on the floors since I have dogs and cats to think about. In bathrooms, around trash cans and on any spots.....I just let it sit and steam for a minute or two without moving it. Works like a charm.
To clean a dirty microwave, I put a cup of plain water in and turn it on for about 3 minutes....long enough for it to boil and steam for awhile. Everything will just wipe right out easily. If there are food odors in the microwave, add a splash of vinegar to the water.