How to clean burner drip bowls of burnt crud and rust?

Hello Sandy! This article suggests soaking overnight in ammonia and scrubbing the next day. A little bit smelly but I bet it works well. You can buy "sudsy ammonia" inexpensively. https://thegardeningcook.com/easy-drip-pan-and-burner-cleaning

Here's a video that might help - https://www.youtube.com/watch?v=E2TpKr3fyY0

If you don't mind using oven cleaner, that will work. I would put down a protective barrier like newspaper or old towels, put the bowls there, then spray. Wait the appropriate amount of time then wipe away. You might have to scrub a bit with a steel wool pad to remove a bit of it.

And after you have cleaned the pans....you can buy disposable foil liners that fit into the pans that help keep pans clean longer and you just replace the foils when needed. Much easier. I've bought these at dollar stores....again Google to see pics

You can run them through a dishwasher. They are very inexpensive, if they don't come clean easily, buy new. You should spend less than $20 on the whole set.