Works great on copper, and most fouling, but not so well on hard carbon. The only other down side is whatever that it has in it for corrosion protection, or maybe it is just so clean, it would take three rounds to settle down. I now run a wet patch of lighter fluid down the bore to remove it. Then a dry patch before shooting, seems to help.
For hard carbon, GM top engine cleaner, a good long soak, bronze brush, then a patch with JB bore cleaner to finish.