I've had good luck cleaning with TC #13 BP solvent, Rusty Duck Black Off, and with CVA Barrel Blaster BP solvents. I wipe down with Ballistol after completely drying. I swab the barrel with Bore Butter.
Brake cleaner will leave your gun thoroughly degreased, with no residue. It's great for cleaning the factory oil off, prior to lubing and shooting for the first time. Some Brake cleaners actually have water in them and take a while to dry out. Those would be better for cleaning the fouling than the brake cleaners without. I don't remember which ones have water in them. We ran out of Toyota brake cleaner at work once and had to use an aftermarket brake cleaner that had water in it. It stunk like bug poison.
I had a buddy who used carburetor cleaner to shoot his homemade 20 gauge BP slug gun. It worked well for removing the carbon based deposits. I don't like the smell of it and wouldn't use it in the house. Besides, his barrel was made from a 1-3/8" OD x 5/8" ID hollow hydraulic cylinder rod. It was chrome plated inside and out. The chrome plating probably did more to prevent rust than anything else. Carb cleaner, at least the one he used, contains no water.
You'd do as well to use ammonia based window cleaner, or make some soapy ammonia water to clean your BP guns(if using real black powder, vinegar bearing windex if using Pyro), if not better than brake or carb cleaner.
I may make a batch of soapy water with ammonia and alcohol, provided ammonia won't react with alcohol. If so, I'll just use soapy ammonia water or windex, followed by denat alcohol to dry it.
You can buy alcohol bearing, foaming aerosol window cleaner from auto parts stores. It may work as well as anything. Don't know yet. Will have to try some and see.
Ballistol seems to work as well as anything for rust prevention. I use it on BP and smokeless arms as well as carbon steel knives to prevent rust. It seems to work well on leather and horn, also, to prevent drying/cracking.
You could always use windshield washer fluid, it's basically soapy water with alcohol.
An aerosol can of Ballistol and a non-aerosol can of Ballistol are 2 very good investments. The liquid is great for swabbing and wiping, as well as mixing with water for cleaning, and using as a patch lube. The aerosol is great for getting to the spots that are harder to access.
JB or Break Free bore paste and Kroil penetrating oil are great tools to have on hand too. The bore paste is great for cleaning barrels/cylinders, and the Kroil is great for removing stuck nipples, or anything else that's stuck/rusted.
Kroil smells like Pine Sol, so, you may or may not like the smell. Regardless, it's a fantastic penetrating oil. I first learned of it in A&P school and now keep a pen oiler full of it in my shirt pocket at work, as well as a can of it in my shop at home. It works well for loosening lead/copper fouling in smokeless arms. Swab the barrel with it and let it sit for a few days.
a 50/50 mix of kerosene/automatic transmission fluid was tested by a major car magazine about 8 years ago and found to be as good as Kroil (the best of the store-bought penetrating oils).
I don't tend to use transmission fluid mixed with acetone as a penetrant, because kerosene is a better penetrant, and acetone will attack plastic/rubber/stock finishes/etc. It's also HIGHLY FLAMMABLE.
If you want to use acetone in your solvent, you can always mix up some Ed's Red. It's basically equal parts ATF/kerosene/acetone/mineral spirits and, if you want, a little lanolin. With the lanolin, it makes a better lube and protectant.
Ed's Red is a smokeless powder solvent, and would need to be cleaned from your BP gun prior to shooting it, but will work great for freeing stuck/rusted parts.
Brownells sells it, but you can find the formula for it here:
http://home.comcast.net/~dsmjd/tux/dsmjd/tech/eds_red.htm
The acetone is a fast acting solvent for smokeless powder residue, as nitrocellulose is solvent in acetone.
One caveat, mineral spirits is not very different from kerosene, and is functionally interchangeable. The naphtha based solvents he mentions are more akin to Coleman fuel.
If you use acetone or Coleman fuel(naphtha, cigarette lighter fluid) you'll want to use it outside, due to the fumes.
I used turpentine(as per the original formula) instead of acetone, because it's what I had on hand. Plus, acetone is at least as flammable as turpentine, if not more so, so the flammability of turpentine is a non-issue, imho.
BTW, excellent info on the rust test. I hate that he didn't test Dexron. It prevents rust better than motor oils. I've never had good luck with Rem Oil. I'd like to see him test Break Free LP as well as CLP, and also carnauba wax, such as stock wax, or aerosol car wax. I used to use carnauba wax on m carry pistols and never had one rust. My sweat can rust nearly any steel, and gun oil is no help. The wax did the trick.
