I can't understand why anyone would use a water based cleaner to clean an old double guns action. If you are using tap water with your spic and span, that has a household softening system, you have about 40mg of salt, mixed in 12ozs of that water.
Mineral spirits is good, as is kerosene, or a blend of both. I've also used lacquer thinner. None of them will cause rust, or, damage color case hardening. If you have a really greased up old gun, nothing cuts the stuff off like old fashioned dip type carburator cleaner-it doesn't hurt case colors, either. I wouldn't use it in an ultrasonic cleaner, however. If you have a problem with the smell or the fumes from a solvent, heres the hot tip-do it ouside.
Best,
Ted
