just as an experiment i chucked a few of my xterra finds in my hornady case cleaner with corn cob media ( might as well use it for some thing dont do any reloading anymore )left them go for about a day and a half and this is the result . not to bad at all so i have chucked in a heap more some have been pre cleaned and some real cruddy . i will give them a few days then pick out the ones that are good enough and let the rest of them do another few days . i think some of the real crusty pennies might not come out to good but will see what happens .