I have had exceptional luck with just oiling them and using desiccant in a safe. The vast majority of my guns are collectable and as such there is a healthy array of walnut and parkerized steel, not so many polished blue ones and a fair sprinkling of “other”. The only issue was with a black powder rifle that I failed to clean fully intending to go hunting with it again and I got deployed a week later for 6 months. That rifle still haunts me. I did get rust on my first AK-47 muzzle compensator but that was due to improper cleaning after shooting Russian Spam Can ammo. Again my fault. Probably 90% of them have not been handled (other than to dig something out) in any meaningful way in several years.
Now if for some reason I had to put my guns “UP” the seal a meal bags are a very viable option but the trick is to keep the desiccant separate from the gun. To do that I would seal the bottom all the way across then seal the top but leave about 1 - 2" gap, then put the desiccant in and seal the top with the air sucker thinggy. Then I could just hang the whole mess up on a coat hanger. I also understand that 6 - 10" PVC drain pipes are handy for “Ready Service” options.