This may not suit all, over the pond in permanently damp air Britain I use the sort of tried and tested method of keeping damp away from guns. I keep all guns individually in its own trunk case with a Silica Gel sachet plus a pound of the stuff in the steel security cabinets we have to have. When I take a gun out to use I remove both packs of Silica Gel with the gun and on the guns return I Nuke both packs of Silica Gel in the microwave to remove the absorbed moisture then return each pack to their original places. This has worked perfectly with no problems for the last fifty years with the only cost being the occasional replacement of the Silica Gel and electricity for the Microwave.
