Of course it's a good method to reduce the syntoms and I am very happy for you. I think it's not true to say that are causes, they are synthoms. The core of stutter is an high level, that's my point. I worked with that, by a method learned in a course, and I succeeded as you. I did my master graduation last year in psychology, with a lot of anxiety of course! I think that my way of thinking the problem seems more logical, because it's better to solve the problem at the roots. Of course, your method improves your self efficacy in communicative situations and I think has effects on the high level