For the deck, the best is a die grinder with these 3M pads on them:
3M-7524.jpg
For the head, I bead blast them. If you don't have a blaster, then the 3M pads for the gasket surface, and a wire wheel for the chamber. You can use brake cleaner yes, but it's kind of expensive for cleaning. I use mineral spirits, or even lacquer thinner for parts wash fluid. Let the head soak in it overnight and it will soften it up.
You could wipe it with a rag a brake cleaner all day and never get it all off. Gonna take a lot more than a rag!