Now here's one for the books.
I have a few farmer friend that reside in central Illinois, and for
years, they have been pouring, spraying, whatever, 90 weight gear oil
into their door panels and quarter panels of their pickup trucks, and
their Grain Trucks, to prevent rust.
I thought they were nuts, but one of them is still running a 59 Chevy 2
ton grain truck, and the darn thing doesn't have a spot of rust on the
body panels.
Neither do any other of their trucks.
They tell me it stinks for awhile, and the doors have to  drain for a
day or two, but the results are quite interesting.
They get the oil when they service their tractors, and pour the oil down
their doors etc.
Talk about recycling!

Later,

Terry