Rebs: My experience with it is that its got a good carbon cleaner, its more a Copper removal orientation wise. Its one of my two mainstays as if I have copper, it will take out carbon layers as well.
That said, for what I shoot, I don't get copper so I use the more effective Carbon Killer 2000 (CK2k)
I have used both on a couple of guns. So far I have hit a carbon layer before done that was not coming off and would shift to the CK2k until through it and if more copper, back to the Bore Tech.