I have a few sks's and I find it quickest to just take the whole thing apart after I'm done shooting and just rinse it down with warm water and dish soap (remove the stock and wooden gas tube cover), then just let everything dry (make sure it is bone dry) and oil before reassembling. Some probably find it overkill but I find it super convenient and gives me peace of mind. Otherwise for guns like my type 81 just running a few patches down the barrel and wiping the chamber and gas tube area a bit has been fine. No signs of rust so far