I think cleaning a barrel is a bit like brushing your teeth, the kind of toothpaste isn't nearly as important as the brush. I have used most of the products mentioned, they all work fine, but I always remove the the barrel and breech seal. I've used both nylon and bronze brushes, they both work well, and neither will harm the barrel. That said, I find that most air rifle barrels seldom, if ever need cleaning with a brush. I shoot only standard power, cut rifled barrels. I expect that HP rifles with poly barrels are a different matter.
I've neve see a cut rifle bbl. in an airgun. Most are button rifled, and a few hammer forged, but not cut rifling. Perhaps, styer? .
Even makers of the top, hand lapped match barrels in pb's say to NEVER use a bronze brush in them. I use nylon only with rather expensive rods with proper bearings in the handle. Many of my ag's are slug shooter with custom barrels. NO Bronze Brushes! Ever!!!
Knife