Speech therapies in long-term thickens stuttering. It works for a while because we experience control over our speaking and it relaxes us. But this type of control is the very same mistake that causes stuttering, our wanting to control our speak.
I wag my head with sadness when I see the videos of that famous program which I won't name because it would be rude. Those poor people are fanaticized, and even if their "control" remains for the end of their lives, they are drug addicts for whom the unwise, profane doctors prescribe another type of drug from the same stem, which of course give them the effect they've starved, but don't cure them and in long terms make them much more sick. They are made stutterer-soldiers, who will eventually fall apart disastrously when their energy drains. As a philosopher I often deal with attitudes like pride, hope, bravery etc. You would be strongly surprised if you knew the real core of them.
You can see the pure horror (the horror that just we can recognize) at times in Gareth Gates's eyes even in his most adequate interviews, if you watch unbiasedly. His castle in the air could fall apart at any time. Saying that "it isn't a cure" is just a temporary help.
I had deceived myself with techniques for such a long time, and been pinched with hunger, that I decided to turn over this issue without expedience; and I've found that therapy can not work against stuttering. It's the little devil again in an angel's vesture.
Pagoclone is not a cure either, but it really works against stuttering. If you believe in Pagoclone, than you logically can't believe in therapies, because the essence of therapy is to satisfy our brain with controlled speaking, and no matter that it abolishes dopamine (like orgasm) for a while, in the end it hightens dopamine (like the more orgasm you have, the stronger need you are developing). It's like switching to another partner to get out of the habit of making love. Or like getting the Kama Sutra to heal premature ejaculation. (Sorry for using sexual methapors all the time, but they are strongly similar to stuttering issues because of dopamine.)