FYI, here's a group I shot last weekend offhand @ 30-yards to win the smallest group contest. In the highest score contest all my shots were in the X-ring in the bullseye. Never missed all day, also went 15 for 15 on the woodswalk with novelty targets out to 80-yards, having used the Joe Wood tool on my 50-cal left-handed Issac Haines flint longrifle.
I find the process goes better by sticking a ball of cotton ball an inch below the bottom end of the tool. After a few turns, I remove the tool and clean the bore to that point, swipe off the tool with the brush side of a file 'card', and put a drop of oil on the lower pilot.