Back in the 90s or early 2000, I came across an article by a professor about ambient corrosion on steel.
He took various coupons (name given to flat pieces of something under testing) of steel and applied to each a different commercial anti-corrosive compound. The winner was a product called Lehigh Valley Lube, and by winner I mean absolutely no corrosion after subjecting the treated coupons to a burn with black powder, rinsing with water applying the anti-corrosive and then leaving them in a 100% humidity chamber.
I bought the product, and it worked really well. I was happy, but suddenly the product disappeared from the market. I called people and found out that the inventor and manufacturer of this product was in the reserves and was sent to Iraq or some other similar forlorn place.
He came back but something was no working with him. He licensed somebody to make the product, but somehow it came out with another name, Shenandoah Valley Lube, but it wasnt the same or as good.
Recently, the original product with the original formula came out to the market under its original name, Lehigh Valley Lube. I dont know if it is the same individual producing it, but the product is the real deal.
I shoot C&B pistols as well as flintlock and in lines, all exclusively with real black powder.
With the flintlock and the inlines, when shooting balls, I moisten the patch with this lube, and also pass a patch moistened with it through the barrel about every five shots. This way Im able to keep on shooting until I cant stand my shoulder.
With R.E.A.L bullets or TC Hunters or similar, I use Bore Butter in the cannelures and a felt wads. Again a swash of Lehigh Valley Lube after 5 shots or so.
C&B Pistols, I use the classic powder, grease cookie and ball.
Now for the cleaning,
All types are thoroughly disassembled and washed with hot water, Lehigh Valley lube and brushes. I have failed to indicate that this lube is actually a pine oil saponification product ( very similar to Pinesol). It is a soap, so I use it in the cleaning process.
Once everything is clean and still piping hot, I dry everything as much as I can, then I wipe everything (inside and out) with this product and let the parts dry overnight. Next day I assemble the pieces back.
In the 15 to 20 years I have been using this product (or its knock-off) I have never had any corrosion in my black powder guns.
I strongly recommend it and no, I dont have any association with the manufacturer or the brand.
Check it out at:
http://www.lehighvalleylube.com/One more thing, it smells nice.