I use this soaked on a bore mop and brass brush on a long rod chucked in my cordless drill.
It is absolutely positiviley freakin' awesome.
http://www.choketube.com/accessories-product-details.php?Choke-Tube-Cleaner-Carbon-Cutter&mf=900
Not only does the citric acid clean everything well, it smells like oranges
But don't drink it.
That's how I clean mine after a match. Especially if it a slug heavy match.
I seem to be getting a lot of heavy fowling from the rio royal star slug in my 930. Any suggestions?