Wipe out is my goto for heavy copper fouling. I've use Barnes, Sweats, Montana Extreme and the Bore Tech Eliminator,but none matches the foam for me. One thing to remember, the foams don't do much for powder fouling, especially burned on cake so you need a different solvent for that.
I simply put a good rod guide in the action/chamber and squirt the stuff into the bore through a soda straw till it comes out the muzzle. The stuff tends to puddle in the bottom of the bore after the foam starts breaking down, so I lay the rifle down horizontally for 6 hours to overnight. Then I patch it out, maybe brush a couple strokes to roughen up any carbon cake, run a couple patches with brake cleaner and foam it again. Then lay it on the opposite side for a few hours. Works every time without all that many strokes with a cleaning rod and it's potential to wear the rifling.