I use a mix of corncob and walnut. Not sure why I do, it just works a bit better. I never use a dryer sheet, when I tumble the cases to separate the media it seems to remove most of the dust. Also I lube my cases for the dies by applying the lube to a thin dish towel and rubbing the cases on this, while flat on a table. The towel picks up most of the dust if there is any and lines the case. If you are getting way to much dust you might consider changing your media. You will know it's time to change your media when it takes like 3 hours to get anywhere with lightly tarnished cases.