I don't know about talking to myself, but I do find describing things or concepts to someone else (almost always in text rather than spoken) helps me understand them better. I suspect it's the act of articulation itself that provides the benefit. So it wouldn't surprise me if speaking to oneself was just as good as speaking to someone else for the purpose.

While I don't know how related it is, I am reminded of this article on the health benefits of expressive writing.

(edit: Fixed link)