cleaning the microwave

Got this from a friend:

1. This is what I do: Put a coffee cup half full of water in the microwave and heat on high for about 4 minutes. Leave the cup of steaming water inside for about 10-15 minutes. The steam will soften any caked on crud.
2. Clean the microwave with soapy water to make sure all food particles are removed. If there is anything stuck on and difficult to remove, spray with a foam cleanser and let it sit for five minutes and then wipe clean.
3. Fill a medium sized bowl with water and pour in one cup of vinegar. Add several slices of lemon or squeeze lemon juice (about 1/8 cup) into the bowl.
4. With the microwave on high, allow the water to come to a full boil, about 4 minutes. Let the water stand for about 15 minutes before opening the door.
5. Repeat this once a month or once a week as needed. With a little care, your microwave should stay clean and sweet as long as you own it.