RE: How do you clean the shotgun barrel properly.
Sounds like that'll do the trick. My system is less involved. I dip the brush in cleaning solvent before I run it through a few times. I take a clean patch and wipe itout. Then I spray some WD-40 down the barrel and another clean patchor two to wipe that out. That's it. The bore is shiney when I'm done.
I don't think that black powder solvent does much for you though. Black powder residue is a totally different substance. It contains salts which attract moisture and cause corrosion. They are pretty much water soluable.