When you have an old cardboard rocket that breaks it's shock cord, ya bilge rat, you usually just glue in another folded paper support opposite t' old one. Then what do you do when that shock cord breaks or burns through? I wanted t' remove 2 o' me old folded paper shock cord anchors t' put in a new on, but I just could nay reach in far enough in me BT-50 body tube t' cut them out with me Exacto knife. Blimey! So I took a 3/8" wooden dowel and glued a 1" strip o' coarse sandpaper around one end. Aye aye! Then I chucked t' other end into me electric hand drill. By carefully sandin' t' old paper anchors out I cleaned up t' inside o' t' tube for a new cord anchor. BTW I was then able t' insert an ejection baffel t' ease those hot ejection charges!