Cleaners such as gun scrubber don’t cause rust. They remove oil and grease which protect from rust. You have to oil after you clean or you will have rusting. I don’t have any Rossi levers but I have original Wins and Marlins that only fire cast bullets, lubed on 450. Loaded with pistol powders such as Unique. They will get dirty actions compared to guys shooting factory jacketed ammo. I haven’t run into any Win or Marlin lever that takes much smarts to tear down. I would caution rookies to stay away from spool magazines on Savage 99s.