I agree that a good .22 bore will be like the Energizer Bunny and just keep going and going without cleaning - until it doesn't. Since I can't predict when accuracy will go south I simply clean them periodically whether they need it or not. I wouldn't want to attend a three day match while wondering if the rifle's accuracy is going to fall off in the middle of the event. I don't mind devoting a handful of cartridges dumped into the backstop to re-season the bore.

"You can lead a man to logic, but you cannot make him think." Joe Harz
"Always certain, often right." Keith McCafferty