He showed three pictures of percussion rifle locks recovered from a New Orleans museum after the big hurricane immersed them in salt water: untreated was a ball of rust, waxed cold had some rust, waxed hot had no rust. It was impressive.
His argument against oil on the wood was that it darkens over time and can't be removed. If you want to preserve it in it's original state for the very long term (like a museum), he said wax is the answer. linseed oilessentially turns into linoleum.