What basically happens is that you take the drug, in a controlled setting, with a licensed therapist, and the ecstasy basically gets you to talk. It allows you to pour out your thoughts and it helps you uncover all sorts of buried memories and feelings that you might not have been able to recover otherwise. Ecstasy is good at doing that. It basically let`s you open a window down into the depths of your psyche, and allows for a vastly more productive therapy session.
I get the same loquacity from crack, except that on crack I maintain a larger working vocabulary.
What makes ecstasy a win (please correct me if I'm off) is that the person that is rolling is not just glib, but also optimistic and mutable.