PB B’laster. About $3-4 at any wal mart. It’s the best stuff I’ve ever seen for what you’re talking about. Look around on the same rack as WD-40. It’s the same stuff, but PB doesn’t evaporate and its WAY more penetrative than obsolete WD-40. I can freep mail details if you like. I have a can right here but FR is weird about pictures
A lot of folks here seem to like it. Many are saying that a homebrew 50/50 mix of acetone and transmission fluid is even better.
I may try both ;-)