Fran, that's the admonitary warning that should accompany the recent post on EZ cleaning with bore snakes and the like. Bore cleaning doesn't have to be hard if you've got the equipment and the habit, but it's not quite as easy as dusting your etagere. I've never seen that 5/0 wool; is it 4/0? Did you apply a bore solvent to the wool on the brush?

jack