swab the bore with Black Off - Rusty Duck when I am about to clean the barrel for good. It is red in color. The stuff really pulls the fowling out of a barrel. I was lucky this year, Wal Mart was selling their end of clearance sale stuff and had five pints of it for a fraction of what they were normally selling the stuff so I took all of it...
No wonder I couldn't find any!

It is good stuff though.