I would boil it on the stove with water & salt. That's how Mom always cleaned the cast iron.
I put Calphalon, Analon & Circulon in the dishwasher all the time. The only damage ever done to my skillets was my sons over-using the cooking spray. There is something in the cooking spray that binds to the non-stick part and ruins it if it's not washed right away. I have worn out my Circulon non-stick pans but it took over 10 years cooking with them daily.
If one of my sons took my good stuff to a campfire--they had better come home with a new set. We have cast iron set aside for open flame cooking & they know it. It's too heavy for me to use.