I know that blackpowder has the bad tendency to cause fouling, enough to start choking up the gun even after 5-6 shots. so I was wondering if it's possible or if any army in the black powder era figured out to shoot sand or fine lead shot out of the barrel to try to scrap away any fouling in the barrel in battle? just load a sand load down the barrel and shoot it into the air, then continue loading and fighting as normal? I think this would have been effective. your ideas?