When I prime them with a Lee priming tool I hold them clamped in the tool and rub them against a rag tied to my bench, or I just rub the stuff off the loaded round. To make the neck come over the expander ball easier, I run a brass cleaning brush through the neck. And don't tell anybody, but I put a drop of gun oil on the brush. Don't need to put much oil on the brush every, 20 or 30 rounds, whenever it gets hard to pull the expander ball again.