Warhawk claims you should clean your barrel every game. I'm going to say no to that one.
I use a custom made 6.02mm barrel in my bolt action rifle. I have not cleaned it since last October. Why? Because that would throw off the established accuracy. Every time you clean your barrel, you change the inner profile of it (by removing things, or damaging if you suck at life). If you are using high quality ammo and being careful not to slam your muzzle into the dirt, you shouldn't have to clean your barrel every game.