I'll go with the martial arts metaphor, it has at least limited application, and is already the reference point for the discussion. As far as there being no rationality dojos, what about Buddhism, or any other mystic or contemplative path along religious lineages?
As far as measuring rationality or rational skills, the main problem is there is no generally agreed upon Truth or even agreement as to whether Truth even exists. This discussion is not about the actual content of truth per se but about the integrity of the approach to truth. This may be soundly based on the idea that we are only approaching knowledge of truth, but truth itself is still not known. So we cannot measure the soundness as a function of measurable results, since the results are either non-existent,unknown or not agreed upon.
It seems that if this is the case then any form of measurement cannot be objective or externally made, but must be subjective and internally assessed. So the question would become not what is true as fact, but what is true as honest. My vote would be for rational integrity as the context within which skill or understanding would be viewed.