I have wrapped Frontier pads around a brass brush on a cleaning rod and put the rod in the jaws of an electric drill to clean the bores of guns with lots of grunge and the cleaning job was quick and thorough.
When I first bought my VHE 28 gauge I did the same but with no solvent... just dry-scrubbed the bores and the amount of lead fouling that fell out onto the white paper towel I had placed under the muzzles was unbelievable
No damage to the bores whatsoever. Frontier pads with a solvent can be used to clean surface rust and crud from fluid steel or composite barrels and even frames with case color with no ill effects at all.