As a person with a stutter that is ‘evolving’, it isn’t for me. I started out repeating a lot of letters, the ‘classic’ stutter. To help that, i didn’t take a breath. I just stopped breathing before sentences. That resulted in my stutter to become more like a block and push stutter. Also the letters i have difficulty with change all the time. I started with p k and t a lot. Now it varies. Think of stuttering as a ball, you keep the ball underwater with your tricks, the ball is still there, just harder to see. Once you take away your hands, the ball will jump above the surface, the stutter will become worse, but then with a lot of trying you are going to be able to pass the ball away and really work on your stutter.