I did McGuire when I was in the U.S. Although I have never used the technique on a daily basis, the whole experience gave me more confidence in a way I know if I stutter I can use the technique taught there as the last resort. The technique also works pretty well for most of us. Some said it was a life-changing experience as one of the challenges that we had was to speak to 100 strangers. That's intimidating even for the normies. The last day we also had to give a public speech where there were a lot of crowds around the area. In addition to that, you will be surrounded by a group of people supporting each other. You will have a mentor that will reach you in the next few months after the program finished. You too can apply as a mentor for the next program. So again, the technique being taught is something physical--breathing technique, but in my case, it helps me reduce my stuttering in terms of how I see my stuttering as something less risky and thus more manageable.