I can't say that I have ever had a problem with moisture in my gun safes. I keep the humidity high in my house because I have several guitars and mandolins. As far as my protectant I have always used 3-N-1 oil on all metal parts except I use granite on the actions of my smokeless firearms. I also use Johnson's furniture paste wax on wood gunstocks. I have used CLP and a few other brands and don't care for the use of CLP in the actions of guns as it will cause the actions to gum up in my experience.