If it shoots good, I would leave the bore as is and just clean the rest of the pistol. Cleaning .22 rimfire bores for the sake of vanity is a good way to ruin them.
I have heard this before I think there was a very long thread about if this is a true statement or not. I am not sure why a .22 would be any different other then there is a greater chance of the rob rubbing on the rifling. I suppose this could cause the barrel to degrade over time, however it is my opinion that the amount of fouling I have encountered would have been detrimental, even dangerous, to leave go. I will continue to clean my .22 cal pistol and take my chances.