Besides proper oiling, there are three basic types of rust prevention: Dry rods™(electrical dryers placed inside the safe). Dessicant (silica gel) packs, and chemical dispersants. The Dry Rod™ electrically heats the air inside your safe to a temperature that dries out the moisture. Unfortunately, this may have an effect on the fire rating of the safe over time, because the heat absorptions/heat sink capabilities of the fire resistant sheetrock are a direct result of it’s high moisture content. Over time the Dry rod™ may actually dry out the sheetrock reducing its heat absorption capacity. No one has tested to find out. Dessicant packs use silica gel to absorb moisture from the air. Silica gel packs are commonly packed with electric appliances & components prior to shipping. Silica gel works but won’t prevent rust if there is any standing water droplets on your weapons. They are re-useable though. Simply use you kitchen oven to bake the water moisture out of the pack per the manufacturer’s instructions and it’s ready to use again. Chemical dispersants like the Inhibitor Plug™ are the most effective method. Chemical Dispersants function by dispersing a chemical vapor that displaces oxygen, thereby preventing rust. Unlike dessicant packs, dispersants work well with standing water, and are even used in tackle boxes effectively. The product can be in the form of chemically soaked paper or more commonly something similar to a bathroom stick-up deodorizer. Over time the chemical dispersant gets used up and eventually it will need to be replaced.