I was always from the school of needing a clean bore to be consistent. The problem was a clean bore never seemed to be as consistent as a bore with a couple of shots on it. I'm talking about using BH 209 now.
So, this season I plan to take a couple of shots, load the gun, and leave it that way for the whole season. It really rubs me the wrong way to leave the gun dirty, but I feel it's safe with BH. Accuracy on the first shot is more important.