Cast Iron cleans up pretty well.
About five years ago we were at a scout camp, I wanted to cook the boys a cobbler but hadn't brought my DO along. Went up to the camp quarter master and asked for a DO. He handed me this nasty rusty thing that still had food in it from at least a year prior.
I found a nice oval fist sized creek stone and started scraping away, then moved to steel wool and a green scrubby pad. Dried it off, oiled it up and threw it on the fire to season.
Made an awesome cobbler with fresh blueberries. WE had plenty of left overs and shared with the camp staff. I also returned the DO cleaned and oiled.
I met one of the staff members 3 years later, he looked an me and said "hey you're the cobbler guy!"
Silver UDS with weber lid, UDS #2 black with a weber lid, 1995 Treager pellet grill, 22.5 Weber