I haven't used ANY kind of oil on the exterior of my firearms in years. IMO oil collects dust particles out of the air and after coating your firearm with any kind of oil over time you're wiping the gun down with grit infused oil.
I use a hard wax such as Flitz's Gun Wax or Renaissance Wax but I expect any good hard paste wax will work. Since the wax dries hard any air borne grit ends up on the wax surface and not the blueing.
Jim

The 2nd Amendment IS an unalienable right.