I suffer from a block myself, and that is what I was referring to by stuttering as for me, 95% of my stutter is blocking, and therefore it is synonymous with it in my mind. I'm glad it works for your clients, however I would disagree that blocks are solely caused by avoidance as whether you meant to or not that is what it sounded like. However I am sure it would be helpful for a lot of people, as even though blocking may not always be caused by avoidance it will be an important factor for some as they will reinforce blocking through trying to avoid it.