I have used with success Montana Xtreme copper killer, Boretech Eliminator, and Shooter's Choice. All of those work well. I'll also add, I use Iosso paste whenever there's a buildup of carbon fouling. It has saved me when I have a severely fouled barrel.
Always use a boreguide. I have a cheap Tipton one that works fine for me.
I use to exclusively use nylon brushes but have switched back to bronze because they clean better and I haven't found any real world negative results using them.