I was very high on the KG products, and they each do what is claimed. But I found that I can use Patchout and get the carbon and copper with one product.
I wet the bore with a patch, then wet a bronze brush and give it a few strokes to keep the carbon ring at bay and help cut through the carbon.
Then a few patches with more Patchout and the copper is gone.
So as not to represent myself as a benchrester, these are varmint guns. But patchout does do as good a job as both the KG copper and carbon products. I dislike solvent based cleaners and have none on hand.