I use the NRA modular pistol rack and it works perfectly. Just take 'em out from time to time to wipe 'em off. But don't leave them in the box and/or holster.
I use Rig Universal Grease inside & out for long term storage then wrapped in waxed paper and then in aluminum foil. Will last forever!
Short term storage I like Rig #2 oil and simply use the "anti rust" brown S&W paper to wrap 'em up and store them in their original boxes. I usually will re-coat them once a year if they have not been shot.
Do not store the boxes in the safe if they are cardboard. They will absorb and hold moisture like a sponge. Make sure all guns have a thin coat of oil on them. Check all of them weekly and reoil if they look dry. The humidity in your house has a great influence on the air in your safe every time it is opened. I have always used dessicant packs in my safe and have never had any rust.