Based on the one case I've heard about, 100%.
Obviously, your definition of success differs from the rest of us, but nonetheless I didn't ask what your opinion of his success rate is. I asked what success rate he claims. If you want others to answer the question which you keep asking over and over again, you might want to try answering the questions posed to you.
Specifically, nobody is going to be able to propose a protocol until you describe precisely what Pratt claims to be able to do and how often he can do it.
-Bri