Don't know what is involved in your process, but recently I made some baked vegies with cheese in a ceramic tray, and the only difference is, I had to run dishwasher on a long mode instead of regular eco mode I use. Then I wiped it with a towel and it was as clean as it was the day I bought it. I don't know what to tell you, it's a normal German dishwasher, nothing out of the ordinary. It's a new one, the house I'm renting in is like 3 years old, maybe that's the difference. But my previous one was some older model, and I also don't remember any troubles with it.