I don’t doubt your program delivers success. Stuttering is a motor speech disorder that is incurable, and to say it isn’t is dishonest. Varying degrees of fluency can be improved and maintained. However, there is plenty of evidence for the placebo effect for stutterers post-therapy. Do you have any longitudinal studies looking at regression for your clients 12-24 months post-therapy? There is no device, chemical, or therapy that has delivered non-disordered levels of fluency for more than 6-12 months. The disorder is cyclical by nature, hence your claim being fraudulent. By all means, continue helping people who stutter. Just be honest about it, instead of making ridiculous claims like some hack selling the next miracle essential oil.