Microwave ovens have become common staples in homes, offices and dorm rooms as an easy way to heat up food. But the inside of many can be a disgusting mess, with old spaghetti sauce splatters and encrusted food covering the walls. A nontoxic way to clean up the inside in a jiffy is quite easy. Fill a microwave-safe bowl with 1 cup white vinegar and 1 cup tap water. Microwave on high for 10 minutes, and allow the cleaning mixture to steam clean the inside. Wipe the microwave with a towel, and it's as good as new.