For about 25 years, the old warm soapy water method worked fine for me. Clean barrels, no rust. A few years ago I switched to Ballistol though and there's NO going back! It's a great patch lube, cleaner and lubricant. I clean with the same 1:7 Ballistol/water mix that I use for lubing patches. I run some dry patches down the bore and follow with straight Ballistol. It has made cleanup much faster and easier and I haven't had any rusting issues with it either. I don't use it for long term rust protection though, so I don't know how well it would do for that.
