At some level, it's the same as rubberducking. The act of articulating slightly fuzzy thoughts in linear language clarifies the thoughts - often to the point where you solve the problem while you're expressing the problem.
I agree with you that articulating your thoughts helps you to identify gaps in your mental processes. But in my experience, nothing beats writing in this aspect. Sometimes I start writing about a topic and I end up discovering flaws that I didn't even know could exist. If you only "talk" it's very easy to skip these points, but I guess one doesn't always have time to write all their thoughts and mental processes.
> Pretty soon, I figured out that if Caroline [Rose, the author of the original edition of Inside Macintosh] had trouble understanding something, it probably meant that the design was flawed.
