Qustion: How do you know that there is a lot of fouling in the barrel? WIthout a good bore scope you probably can't tell that you do/don't have it coppered up pretty good. To soak the barrel you would use a chamber plug and then pour some safe solvent into it like Handloader1 recommends. I usually put my guns thru the Foulout III operation everyyear after hunting season to thoroughly remove copper . During the year I clean them after each use with copper brushes and Butchs Bore shine or Shooters Choice and that pretty much keeps the copper at a tolerable level. JB compound is used if I can't get the bore well cleaned the first cycle..wet patches/brushing.