I've been using Sea Foam for about two years. I used it to clean a carbon ring out in my 6.5-284 Norma, with lots of elbow grease. After that ordeal, I started include it as part of my regular cleaning routine. Ring has not returned, yet. Just picked up a bottle of Break Free CAC Carbon Cutter. Thought I'd give it a try, so can't say what it will/won't do.
For a few years now I have found KG1 works very well on carbon followed by KG12. KG12 is a copper remover but I have found it also removes carbon. My findings are backed up by visual checks with a Hawkeye bore scope.
I just had a carbon ring in my 6.5 PRC that two 24 hr soaks with wipeout followed by two hours of soak/scrub(nylon brush) with wipe boretech eliminator after each application of wipeout would not remove. I even tried jb bore paste with no luck. I ordered some C4 and the ring was gone in one ten minute soak and a few seconds with a nylon brush. It was difficult to see with the Lyman bore scope. The Teslong bore scope is a game changer for those who don't have the money for a Hawkeye. To be honest I am not sure how much better it would be. The Teslong displays a very good picture of what is going on in your barrel.
JMHO, but there is no one carbon (or copper) cleaner that is the best in all situations. Best practice is to have a couple of proven cleaners on hand and rotate through them when cleaning.
And, I would gently suggest that the unfortunate reality is that unless you have a bore scope to check your bore after cleaning, it is really really hard to know how good your carbon (or copper) cleaner really is. Again, JMHO.