Hey guys; I have a set of calipers broken down and am completely rebuilding them; seals pistons. Came off a nicely neglected street bike and are quite filthy. When doing a complete tear down like this I would like to get them basically 100% clean inside and out. A lot of the black brake residue is stuck on real good, i don't want to get too aggressive scrubbing if i can avoid that. Any insight on something I could soak them in? On person mentioned Vinegar may work?