I like to use the stuff on barrels of my surplus rifles after I've taken care of the corrosive salts, and my 1911 barrel is really hard to get clean for some reason so I use foam on it. Is there anything harmful about this stuff. I just got a can of Outers Foaming bore cleaner a month ago for the first time so I haven't been using it long.
About my 1911 barrel I don't understand why but every 1911 I have ever had has been a bitch to get most of the fouling out compared to other pistols. My XD barrel looks brand new after 10min of cleaning and it has thousands of rounds through it.
Shouldn't be any issue... I use Break-Free Bore Cleaning Foam & Carbon Cutter all the time without any side effects. Hell, some times I let it soak in the stuff... makes it easier to clean.
As for the barrel of a 1911... not sure about that. Never had any issues with my Colt or Springfield being harder to clean than anything else. Are you using the correct sizing for the barrel? Always change out a wore brush... after couple cleaning, the brush doesn't make contact with the groves anymore.
I usually downgrade the 45 brush for 40, and 40 to 9 as I wear them out.... works out great.