My microwave looked like one you might see at your job. You know, the one everybody uses but no one cleans. The insides were covered with grease and food particles. I keep a set of plate covers on top of the microwave, but apparently none of us use them.
I heated a bowl of water and baking soda in the microwave for four minutes. While the chamber was still hot from the steam, I sprayed in my favorite cleaner (Awesome!). It looks respectable again.
I forgot to time this, so I’m not sure how I did on time, but a minute or two extra was worth it.