I have had a Gun Safe for over 20yrs and the humidity here in FL is a killer. I set mine on 90lb roofing paper and keep two small containers of Damp Rid in it. I buy the filler at K-Mart about every 3 months or so. The containers get filled with water and have to be dumped out when the filler is gone, but it's very caustic and you have to be very careful that you don't spill it on the guns. My guns look like the same day I bought them.

Down herein West Cenral FL., the humidity is so bad that Welding Hoses and Air Hoses don't last long. The only ones that last longer are the Good-Year red rubber hoses. That's how bad the humidity is down here.