I do not clean every shot but I try to run a patch down the bore after every shot to wipe out some of the gunk. I have shot 3-4 in a row with no patch without ill effect, but they do get dirty quickly. You do need to scrub it down after each session before putting it away!!
I run a patch with some solvent (some people use saliva) on it down the bore every 3-4 shots, followed by a dry patch. Breech plug is left in until final cleaning after the range. I use Bore Butter for a bore preservative after final cleaning.