Sweets used to be a good strong copper remover, but it changed and just not as effective. Same with Hoppes 9, but the good stuff ended decades ago, one of the ingredients was removed. But it sure smells good!
JBs and IOSSO does a great job, but not for cleaning every time. EdsRed might remove a little carbon fouling, slowly, but that's it. It has nothing to attack copper fouling.
Wipeout foam is great for a heavily fouled barrel, let it sit over night and you'll be surprised at the patch. I use the Wipeout Patchout, the accelerator, and the Tacticle Advantage, all from Wipe Out. They do a decent job, but after a yardage of shooting, I can feel the patch tight right in front of the leade. Back to the usual solvent and bronze brush, and the tightness is gone.
By the way, I make my own solvent mixture. I use the old GM Top Engine Cleaner as the base(no longer available), 28% ammonia, peroxide, and kroil. One batch will last most of a season.
Still, frequency is a key factor in my opinion.