I had always assumed that the current primary purpose of the Lesswrong site is to spread the word - to increase awareness of the existing body of knowledge related to rationality, focusing on proof for the benefits of becoming more rational, and enumerate the techniques required to obtain it, only indirectly supporting the actual work required for becoming more rational. Similar in nature to the Harry Potter story.

For the actual practice, at least in an online setting, I imagine that something closer to the Lumosity site would be appropriate.