I clean the guns I use on a regular basis, particularly after being exposed to moister. The other guns (safe queens) get a through cleaning (mostly oiling) yearly, usually in late January, or right after the close of deer season. This started several years ago after removing a prized .22 Marlin 39A Golden Mountie, (The gun was special because it was a first wedding anniversary present from my wife in 1959.) and finding the gun coated with rust and with slight pitting on the receiver.
I built a cleaning tank out of a 12 inch diameter, 60 inch long piece of PVC, capping both ends, then cutting about a quarter off length ways to form a vat. I fill the vat with 4 gallons of PD680 (cleaning solvent), and add 3-4 cans of automatic transmission fluid, I then remove all the grips from all my hand guns and let then soak over night in the mixture, the next day I take them out and stand them barrel end down in another vat fixed with dowel rods that insert into the barrel to hold them, and allow the excess oil to drain off. I then blow them off with compressed air (using a filter system to eliminate moister), apply a light coat of oil, put them back in their box or case, and back into the safe. I do the long guns the same way, except I remove stocks and scopes before the metal goes in the vat, this is only for the safe queens since removing the scope and stock requires zeroing the gun again. This takes a lot of time and effort, but it gives me something to do after deer season while it is still too cold to do much else. I also recommend a barrier paper or gun sock be used on those that don't get used or handled often.
Another thing that I do, I keep a shop rag lightly coated with Breakfree a plastic zip lock bag in the gun case of all the guns I use on a frequent basis, after each use the gun is wiped down before going back in it's case. Some of the things I do may seen a little extreme, but I look at them as cheap insurance for my investment.
