This might help !
Taken from Wikipedia
Aging, solidification, removal
Cosmoline that is fairly fresh, or that has been
hermetically sealed in a plastic bag or
shrink wrap, remains a
grease-like viscous fluid, and mostly wipes off with a rag, leaving only a thin film behind. Cosmoline that is older and has had air exposure usually solidifies after a few years, as the
volatile hydrocarbon fraction evaporates and leaves behind only the waxy hydrocarbon fraction. The solid wax does not readily wipe off. It can be scraped off, although the scraping is laborious and leaves crumbs to be swept or vacuumed away. A useful method of cleaning a tool of crusted cosmoline is to allow a penetrating oil (such as
WD-40,
CRC 5-56,
CLP, or equivalent) to soak into it for several minutes or hours, which typically restores it to a viscous-fluid state, allowing it to be wiped off. An additional method of cosmoline removal on new parts is to use a closed-cabinet
parts washer that utilizes the power wash process. Removal of cosmoline with an aqueous parts washer requires high heat, the proper aqueous detergent, and the correct hydraulic impact pressure. Most of these "washing" methods will create a difficult-to-dispose-of toxic sludge.
Cheers
Bucky