Try this: https://www.hometalk.com/29142677/how-to-clean-your-oven-with-just-baking-soda
Here are some great oven cleaning posts on Hometalk: https://www.hometalk.com/search/posts?filter=clean%20oven
I used the baking soda paste idea and covered the entire inside of my oven with that paste. I had a white oven. LOL Anyway, I left it overnight then cleaned it out in the morning. You do need a lot of fresh water for rinsing. I also used vinegar in my water for extra punch. It worked well. I hope that helps. Wishing you the best.