An old friend of mine has done a lot of smallbore shooting around the world with the US team. One trip they stopped by Anschutz factory to try out some new rifles or something. After the Americans were done shooting, they broke out the cleaning rods, etc. The Germans just stared at them.
During my target shooting days we always cleaned, but found it very difficult to notice whether it 'helped' or not. Of course rimfires are finicky with ammo, etc. and different ones will behave differently. Cleaning the bolt face, firing pin, etc. is obviously very important especially with the sticky ammo types. The slimiest we ever used was old Winchester Mark III, especially when it melted during a warm outdoor match!