Not true (and I speak from personal experience). A client may know how to do it, may talk about doing it, may even believe they're doing it, but actually doing it for reals, not so much. There's a really simple reason for it too: it HURTS LIKE HELL!!
We are programmed to avoid pain, but this involves literally walking straight into it with eyes wide open. It is a very painful, (shameful) thing to admit out loud that it is our own patterns , our own beliefs, our own doing that is causing is all this pain.
We want - I want my T to take my pain away, to make it all better, but he can't do that. He's only a man after all, he doesn't have to power to help me, only I have that. He can show me the path, but I have to walk it. If I refuse to walk it because I am too scared, too ashamed, too little, then there's nothing he can do for me.