Hoppe's #9 is very weak at getting heavy copper out of a barrel. Better solutions are Barnes CR-10, Sweets, Hoppes Benchrest, Shooters Choice Copper Remover, Butch's Bore Shine, water, kool-aid, almost anything other than #9.
The Foul Out II will run around $70 on sale. It's not too messy or hard to use. You only need it when you need it, if you know what I mean. If you clean regularly with the Cu solutions, you'll probably never need it.