Well, the first thing you can do is try to get as much moisture out of the air as possible. I like to use de-humidifiers in my gun room where my safes are. I also clean my guns with G-96 Gun treatment and it does a great job against rust. Not only is it a great cleaner but itcoats and protects the gun as well. I also like to open my gun safes often to make sure they keep dry (plus I get to look at my guns). I don't put any kind of rods or moisture removers in my safes though they do work to keep the moisture out. I just treat the entire room and keep the humidity levels down with de-humidifiers. Living in Illinois that's not an easy task as the summers get very humid but it has worked for me.