For my scoped hunting rifles, centerfire (and especially with my muzzle loader), once I get a 3-5 shot group where I'm aiming (usually around MOA @ 100 yds.) I'll clean the barrel and wait for the barrel to completely cool off. When I can put the first CCB (clean cold bore) in the bullseye at 100 yards I call it good. Depending on the rifle/caliber that usually gets me poa/poi from 100 out to around 180 yds. If I'm shooting 200 yds. and beyond, I will confirm zero at that/those distance(s). I believe in the 'One shot, One kill' adage. At the beginning of each hunting season, I will take a shot or 2 to confirm zero before heading into the woods.
For my rimfire rifles I just zero them and don't clean the bore until accuracy starts to fall off. I will clean the chamber after shooting to avoid any carbon ring build-up.