If you don't clean your pellets before shooting them you are putting a bunch of junk in your rifle.
I always clean and lube them before feeding them to my pride and joys.
I method I use is to wash them in hot water and Dawn dish washing detergent, the reason for the dawn is my brother is a Arson inspector and this is what he uses to clean his hands when training the sniffing dog.
This is the only thing that will remove the oil and gas he uses to train the dog, also when collecting samples from a fire he washs his hands with dawn to prevent cross contamination of samples.
I was in a hurry and just lubed a new tin of .22 F.T.S.'s and this is what was left in the tin I use for lubing.
A plastic zip bag, hot water, a dash of Dawn, shake awhile and drain through and screen, rinse with hot water and set on a towel to dry.
I clean a large tin out, like an old tin from chp's works good, 3 drops of napier in the lid and in the bottom, dump in the cleaned pellets, close and rotate a minute or two. Now you have clean and lubed pellets for your pride and joy that will now screw up the barrel and cause shots to go wierd places.