Ed's Red: 1 part unscented kerosene, 1 part unscented mineral spirits, 1 part synthetic automatic transmission fluid. You can put a little acetone in this mixture but don't use it on painted or plastic parts if you do and use a glass container. I have 30 gallons of this stuff in my parts washer no acetone and it works like a champ. No I haven't burned the shop down yet. I think the ATF raises the flash point and I ran my pump in water pipe for conduit. WD40 cleans good but it must be dried / wiped off well, as it will kill primers. Break cleaner works good also, but the part will be bone dry when you are finished and it will eat some plastic and paints, oil the part if you use break cleaner CLP, Marvel mystery oil (cleans best), or synthetic ATF which wont eat gas system O rings. Cosmoline wont hurt anything heat it in the wife's oven (I don't have one of those , but I do have an oven) and then wipe it off.
Richard