I tried one can of foaming bore cleaner (I forget the brand I think it was by CVA) and it was nothing special. I used it as directed. After it was done, I put some Birchwood Casey #77 on a patch, swabbed the bore and it came up dirty.

A real cheap cleaner that really works and if you get it don't let the better half get their hands on it or they take it away.. is called Simple Green. That stuff really cleans fouling. Actually it cleans about anything you like. I purchase it by the gallon. It will even clean the soot off the inside glass of my wood stove and believe me, that stuff is hard to get off.