Have a stutter too, I was in speech therapy from when I was 7, and one of the techniques that worked best was to focus on breathing and relaxation. When I blocked on words, the levels of tension in my body was/is extremely high. Specifically in my diaphragm, when there is tension, my chest is more rigid and the tension in mouth and tongue is so much stronger. So they had me focusing on relaxing my diaphragm which would allow the other tension to be less. So to focus on my breathing and being relaxed. (and yes I could sing fluidly, but my speech was very very blocky.)
The interesting thing was that this required thought and awareness, which is a bit difficult when you are younger. As I got older my confidence came, so became more relaxed in company and therefore less tense and so likely to stutter. I still do on occasion, but I am less concerned about it these days.
Something I've always been curious about: does the physiological stress or the psychological stress come first? Do you think "I'm stuttering" first, or does that tension you experience precede it?
Good question. For me it's just a mixed bundle and self fulfilling. I can map out the stuttering words and sounds and I jam up when I realize I can't replace the word elegantly. My stutters are now so far between that people are thrown back when it appears suddenly.
There is an anticipation you experience, it feeds back from previous instances of stuttering on a sound and can ingrain itself pretty strongly in your psyche. There’s a word for this, “anticipation” or something.
I was in speech therapy from a young age, too, and breathing helped, but I had to go a bit further than just focusing on breath control. What really flipped the switch for me, after I had breath control down, was elongating the initial sounds of words when I felt a bit unsteady in my speech. This gets a bit complicated for stop consonants, like b or d; luckily, drawing out the sound made when everything is "in position" helps. For b this is m, and for d it's n.
Anyway, it's a "resetting" technique, forcing me to coordinate everything by holding things steady for a bare fraction of a second when they threaten to fall out of sync and cause a cascading failure. It wouldn't work without breathing, but breathing alone didn't quite do it for me.
(Interestingly, relaxing wasn't quite a necessity: I never stuttered when I yelled in anger.)
It is worth it to keep going, he is figuring things out still, both himself and this thing he is figuring out, and the technique and insight may not be the cure now but at some point he will piece things together and what he has learned may help.
The interesting thing was that this required thought and awareness, which is a bit difficult when you are younger. As I got older my confidence came, so became more relaxed in company and therefore less tense and so likely to stutter. I still do on occasion, but I am less concerned about it these days.