I guess you would need Like-material. I don't do any metal detecting, but from what I have gleaned from the reality show, that they can determine a makeup of the metal right from the surface.
I guess Silver or Precious metals would be hard as far as decoys?
Anyone know where to get their hands on some cosmoline or similar storage grease?
How much are you looking for?
We have used it for years, and I don't see any way the original military cosmoline would be able to be applied in aerosol. It is much heavier, and tackier than gun grease, and takes effort to remove.
http://www.commercialforms.com/Detail.bok?no=172