Being the sceptical type, I take what I read on the Net with a grain of salt, so I had to check this Chore Boy idea out for myself. Here's the scoop:
Went to the nearest likely place to get a copper pad, which happened to be a Dollar General. The package said "copper scrubbing pad". Checked it with a package of refrigerator magnets hanging nearby. Seemed OK, so I bought them. Checked them again with a bigger magnet at home. Thunk! They stuck. Pulled a strand out and scrubbed the copper off with emory paper. Steel underneath the copper. Got my money back.
Went to Wally World. They had ScotchBrite brand, which was plainly labeled "copper-coated". Reject.
Went to super market; found Chore Boy, which was labeled "pure copper". Checked with a magnet: Nothing. Success.
Now here's the secret. The pad is a knitted -- yes, knitted -- tube rolled up like a sock in your sock drawer. Find the two places where it is tucked inside itself, and untuck it. It will now unravel just like a knitted sweater, if you start at the correct end of the tube. I was able to pull four or five-foot strands from it. Spin several feet around an old bore brush, just like jhenry said before.
I had been pushing some LWCs pretty hard through my Blackhawk .357, so it was leaded up pretty good. Ten strokes with that bore brush and some Hoppe's No. 9 and the barrel looked like it just came from the factory.
The copper is way softer than the steel barrel and probably softer than the bronze bore brush, so it won't hurt a thing. JUST BE SURE THE PAD IS MADE OF PURE COPPER.