I watched a couple of his training sessions on YT. Funny thing is that nobody actually used those crutches when speaking to him - sure, they could repeat them after him, but when it came to actually speaking they just resorted to their regular stuttering speech. It's hard for me to believe people use those crutches in regular, every day situations, if they cannot apply them during coaching sessions. Additionally, all his coaching sessions (or at least those available on YT) are held in a relatively safe environment. Why aren't people, who use his methods, posting videos of them doing public speeches, presentations, phone calls, talking with strangers etc? After all this should be entire point, especially with your claims about anxiety. And btw, I do stutter occasionally when I'm alone - especially after hard weightlifting sessions. They are taxing on the nervous system, so I believe this is the main reason behind it.