During my recent cam replacement I had a number of parts which were greasy and covered with varnish. Cam bearing caps and nuts, especially. I had used Simple Green in the past for cleaning engine areas, but not as a soak. I poured enough SG in a coffee can to cover the parts and left them overnight to soak. Next day, they were spotless. Just rinsed them with water and immediately covered with oil and assembly lube so there would be no oxidation.

This stuff is supposedly biogradeable, but it will eat skin oils in a hurry. Perhaps it wants your skin to become part of the environs.

Anyway, it worked for me and is available by the gallon. Am saving the leftover fluid for the next job.

dick