Summarize the following:
Grab some fresh fruit, like a couple of oranges or a lemon. Peel the oranges or cut the lemon in two. Fill a bowl with 1 or 2 cups (237 or 473 ml) of water. Add the orange peels or lemon halves. Microwave for four minutes (or less, if needed, to avoid burning any fruit breaking the water's surface). Let it sit anywhere from 30 minutes to 12 hours with the door kept shut. This is definitely advised if you used nail polish remover. Citrus should eliminate any lingering smell from that. Open a new box of baking soda or simply place an old one inside your microwave. Let it sit for 12 hours so it can absorb any smells that still linger. Alternately, dump fresh or used coffee grounds into a cup or bowl and use that instead. Either practice is a good preventative measure to keep slight odors from growing stronger between uses. Ideally, give the inside of your microwave a quick wipe down with paper towels and a mixture one part water and two parts vinegar after every use. If that isn't possible, keep the door open after each use to air it out. Then give it a thorough cleaning at least once or twice a month. Any spills or other large messes should be cleaned immediately. If you don't, these will cook and recook and stink up your microwave with each subsequent use.
Microwave something citrusy. Absorb odors with baking soda or coffee grounds. Clean regularly to avoid more smells.