This may have been over previously (been a while since I read through all the posts).
But the general though is we need to keep out barrels as clean as practical, basically clean after each range use.
Not to get the bore spotless (aka remove copper fouling and everything) but to at least remove carbon, powder residue, and general crud that builds up.
So you need a cleaning product that will remove loose crud, carbon, not attack metal (chemically or physically), preferably not be water base, and preferably offer some protection.
I started using BoreTech products a while ago, I know mostly just use C4 as I shoot 99% 22lr and want to keep in top of carbon in the chamber.
The general thought is you don't want to remove all the good fouling (bullet lube and lead) but again loose crud, carbon, and definitely the carbon ring. The Boretech C4 seems to work well on the carbon, but as I tend to just dry patch the barrel (centrefire I always run a oiled patch then need to run a dry patch before shooting), there is some risk to corrosion from the water base.
I also hate the residue it leaves on your fingers, and worry about it possibly building up in the trigger group over time.
I'm guessing kerosene or mineral spirits would be a good alternative as a carbon cleaner (not so much the smell or oily residue though) is it going to be any better than Hoppes or Shooters Choice? With the latter two offering some protection without the need for running an oily patch after cleaning, and should be less likely to gum up/build up as most of the ingredients will just flash off.
