I have just begun to try it, I'm in day 2 exercises. I think it provides valuable information to understanding stutter and the causes regarding it (I didn't know for example that stutterers shift the workload involving speech to their right side of the brain whereas fluent speakers use the left side of the brain). In addition to that it provides vocal exercises. And by understanding stutter you could be one step closer to get rid of it. I see no harm in doing anything that might be helping, whether that is physical exercices, theories or other things related. Different things work for different people. If you want good free help, check out SpeakingVan's youtube channel :) It has helped me.