Recently I had a sweet potato explode in my microwave! The worst of it was the terrible burnt smell that lingered, especially every time I used the microwave. To get rid of this unpleasant odor I combined 1 cup of water with 1 1/2 cups of white vinegar in a spray bottle. I sprayed the area and even the inside of the microwave and then wiped with a paper towel.This may happen to you while popping popcorn or something else. It works on fireplace odors too because the acetic acid in the vinegar destroys the odor-causing compounds so the air you smell now will be fresher.