I saw a person who beat it completely. Can I do it too?

I saw a person who beat it completely. Can I do it too? I saw this fitness channel of an ex stutterer on youtube. Tadhg reynolds. He basically made a video on how he used to have a stutter but he did the McGuire Program at the age of 18 and it fixed it. Thing is he's cured 100% now. He's extremely fluent now (at least on video). Like you can't tell at all if he has a stutter or not. I'd highly encourage you guys to check him out. My own stutter has improved signifigantly over the years and I just have a small 1-2 second block now. I do have the occasional bad days where I have multiple blocks, but im far better then when I was 14 and could barely speak. I know this sub has a thing about trying to debunk claims of cures and labelling alot of techniques that help as"novelty tricks", but I've been asking myself if people HAVE done it, and i've improved signifigantly msyelf, is it still possible to beat it 95-100%? Is it (at least in my case) entirely a mental thing? How would I know if I am one of the people who can beat it?