After a few semi-successful attempts to polish the faces of mold halves, the thought occurred to me that maybe a properly sized bore mop might serve as well as a cast slug when polishing. The mop, being very pliable when saturated with polishing compound, toothpaste, etc. would possibly have less tendency to eat away the metal at the cut line and deform the mold half {I guess you can tell why I wrote "semi-successful"}. Screw the mop onto a cleaning rod and turn by hand or with a drill. Has anyone tried such a device, or am I to be the sacrificial virgin?