Gunslick copper solvent

I just bought a new cleaner or at least new to me it's called Gunslick copper-klenz. It seems to work pretty well for me at least better than hoppes. Lately I have been having lots of trouble with copper fouling which I haven't figuered out so this stuff has been a godsend of sorts. I bought it at wally world and it was around 6 bux a bottle which is about twice hoppes. But if you have problems with copper fouling this stuff is worth it.