Ken and everyone:
Hot soapy water is a very TRADITIONAL way to clean after firing blackpowder guns. The reason it is traditional is simple: water-displacing petroleum oils and cleaners haven't been around for more than a couple of generations!
Black powder residues contain salts, sulfuric acid, sulfurous oxides, hydrocarbon soot, and burned oils, grease, etc. The residue is clearly hygroscopic, and will suck moisture out of the air and rust gun steel in a matter of hours. The oils, grease, and carbon will dissolve in nitro powder solvents, but not the acid and sulfur oxides, and salt residues. Oiling after a water cleaning protects the steel, of course. Modern water displacing cleaners protect even better than oils. BreakFree CLP is one of these products.
The military changed to using CLP for cleaning large caliber cannon, even for ships at sea. The salt-air environment is obviously hard on gun steels, but the CLP proved so good that it replaced the old-fashioned sodium carbonate cleaner.
:shock: