A question just occurred to me. There is a type of basil that is somewhat holy in southern india - referred to as "tulsi." Often folks will drink tulsi infused water there. My mother insists that this is not the same as Thai "Holy basil"--I have never had tulsi in India but always thought it was the same and that the holiness came from earlier Indian buddhist proselytizing in SE Asia.
Anone have a definitive answer?