If you clean immediately after shooting at the  range while the barrel is warm, it helps with carbon removal. Cleaning between relays also helps to keep the carbon buildup in check.
Quality bronze brushes! I like Pro Shot brushes. The only thing I use nylon for is brushing case necks now. Even the primo, stiffer,  nylon brushes are inferior to bronze brushes IN MY EXPERIENCES.
Cleaned a barrel with Iosso nylon and C4 over a 24hr period, wet patch roughly every 4hrs after initial patching and brushing until bed time. Brushed again the next morning, according to the patches, the carbon was gone. Bore scope said otherwise. Cleaned again, but with bronze brush and the patches were filthy. This was with a BR gun with a Kreiger barrel with less than 50 shots on the barrel.
I can’t duplicate other people’s claims and results when it comes to nylon brushes and cleaning products. Why, I don’t know!
Since getting a bore scope I have become so cynical of the gun cleaning product market.
Fellow local BR competitor and I have had numerous conversations about cleaning. Best barrel he ever had, a barrel that continuously shot 250, high X count scores. Only thing that barrel ever saw were bronze brushes and Wipeout cleaner, and a VERY INFREQUENT cleaning with abrasive for a few strokes when the gun didn’t score to expectations. He never had a bore scope and said that barrel probably looked awful if a scope had been ran down it, but it shot lights out. Moral of the story, let the barrel and scores tell you what it needs.