We had somebody watch our house for a few days. While the person was here, they cooked eggs in our bowls in my microwave and didn't clean them. So, we came home to four bowls with stuck on egg. We tried and tried to get it off the bowls, but we weren't able to accomplish it. We tried soaking it overnight, using the dishwasher on high temp and sanitize, and I spent too much time with a brute force attempt. Well, I was prepping for a chuck roast cook when it hit me. Let's cook the bowels! I LOVE these bowls and the matching plates. I've never held or eaten off better dishes. Here they are raw, uncooked. At this point, they have been cooking for an hour. I removed one for a test and the stuff almost came off without much effort but I wanted to let the others cook for a bit. I let the rest cook for about two hours, and the crud came right off! I will be making this again if needed. The hardest part was getting them out of the bath. I ended up using a metal spatula and tongs.