Instructions

1. Fill the bowl. Pour about 1 cup of water into the bowl.
2. Add lemon or vinegar. Squeeze in half a lemon and drop the rind in too. Or add a tablespoon of white vinegar.
3. Add a wooden stick. Stand a wooden spoon or chopstick in the bowl. It gives bubbles somewhere to form so the water doesn't boil over suddenly.
4. Heat it. Microwave on high for 3 to 5 minutes, until the water boils and the window fogs up.
5. Wait. Leave the door closed for another 5 minutes. This is where the magic happens.
6. Wipe. Take the bowl out with oven mitts, lift out the turntable, and wipe the inside from the ceiling down.