You should be able to find similar posts on this sub, but generally you will find people (a) a smaller contingent of folks who swear by it and will fight you to the death defending it and (b) a large portion of people who have either tried it and not had success/people against the very idea of it. If you look it up, the principles of it all seem pretty sketch to begin with (if slowing down actually cured stuttering, it would have worked by now). And, my fiends who have gone though it (i haven’t), all regret it save one. That one person is a very fluency focused person who “practices her tools daily”. So, yeah.