I had some success at a 2 week intensive program. When I say some success, I mean, I left the program completely fluent, but it came back a few months later. I have mixed feelings about it. A part of me feels like I could have and should have practiced more after the program ended. But another part of me feels like I practiced a good amount. All of this to say, I know for a fact it CAN work. I didn’t have long term success with it but I think many others have. No bullshit, when I left the place, I was fluent. And it sounded natural. Most of the other people there had pretty good results. A few didn’t improve much at all. The place is [HCRI](https://stuttering.org) in Roanoke Virginia. The techniques we learned were - diaphragmatic breathing - stretched syllable - gentle onset / amplitude contour I’m on my phone right now but once I’m at my computer, I’ll try to describe each technique.