A reader has asked me about my opinion about the Valsalva theory and treatment created by William Parry. Check out Parry's website. As two year ago, I have not made up my mind.
At best, his theory is a partial theory of stuttering and only focuses on the stuttering and blocking events. For Parry, the mis-use of the natural Valsava mechanism greatly blows up the symptoms of our inefficient speech system. Relaxation of the muscles involved in a Valsava mechanism helps reducing the tension and severity of symptoms. It seems to me that his method is similar to muscle relaxation techniques.
I have added a diagram that I found on his page that illustrates his theory. Have a look at it! Let me know of your opinion.