I have a tip to clean up anything that ends up sticking in the microwave.
Fill a cup with warm water and place it in the microwave. Also, warm a cloth and place this in there too. Then, microwave both items for about 20 -30 secs. Then, the air would have humidified and things in the microwave loosen up. Then, wipe down with the water and cloth. This method gets rid of the dirt quickly. EASY PEASY!