My .32 does not collect fouling, yet it has wide lands and narrow grooves, the opposite of what it should be. I still use combinations that more than go to the bottom of the grooves, hence it's 'clean' shooting.
If you always more than fill the grooves (compression in the bottom of the grooves) with ball and patch, the barrel will NEVER - ie: cannot collect fouling - no matter the bore size, as long as the patch is wet with a water based lube - especially spit.