Originally Posted by jkliphouse
only used soap and water on these?
Laundry detergent, lots of hot water, various brushes, and a "slop sink". If really caked on, you'd want to use engine degreaser or TSP first (outdoors; runoff?).
I've heard of folk taking their parts to coin-op car washes! But I'd instead get the worst off myself, then go to a machine shop for "hot tanking" of the parts.
In the really old days we could use aggressive solvents. Or even TCE in a vapor hot tank, but TCE was now banned for good reason. It was great at cleaning mechanical parts, though!