I have done it although I don't have a stutter. (I'm in this sub for my son.) Landmark helped me greatly to improve my relationships (forgive my dad) and there was a physical energetic release as well. I felt my posture change,my chest felt freer and my face muscles on my forehead relaxed (where I didn't even realize they had been tensed.) I am mentioning the physical releases to you because it was something inexplicable that happened and so you never know something like that may improve your stutter. People who say it is cultish--sure whatever. But bottom line is that it helps people live better lives and their business model is word of mouth and you don't have to tell people anything though they encourage you to invite people.