Opinions vary widely about how to handle pellets, i.e., washing and lubing, individually weighing, checking for head size variance, etc.
My experience over now tens of thousands of pellets and nearly two decades is that unless you are going for an olympic medal, and your shooting is 40 yards or more, with a good rifle and talent, once can hardly discern a difference, especially with the .22 and .25s of doing any of the above as compared to taking good quality pellets right out of the tin.
I have done it all, and unless I really have something I am trying to prove, not any more. I do keep some weight sorted pellets in each caliber, sorted to +/- .005 grain, for when I really want to keep the group sizes as tight as possible. This seems to make the biggest difference in my rifles.