I use Lee Precision Resizing Lube which is designed not to affect any powders during storage. I spread it very lightly with my fingers on the outside of the brass and place some lube on a KleenBore Cotton Bore Mop to lube the inside of the neck. It makes sizing much, much smoother/easier to lube the inside of the neck. After sizing, I use another dry Bore Mop to clean the inside of the neck and a rag for the outside of the brass. I don't try to get every bit of lube out of the neck, just a run through with the dry mop. Never had a problem using this procedure.