Me too. You can even go faster by sealing the food with some insulator (e.g. plastic or tinfoil) to make it retain heat and cook faster in the microwave.
I don't know the answer to this, but my grandma has an old microwave with a metal grill that your food rests on (like a rack in a conventional oven). I am not sure if it is the type of metal or the shape (it has a squiggly bend on each side, in the middle[0]), but it's definitely possible for metal to go in the microwave without sparking.
