"Also, He is not smoking a 'spliff' or a 'roach' that is a mapacho, or a cigarette of jungle tobacco. Mapacho smoke is used in many types of ceremonies in the Amazon. It is regarded and a cleansing tool, to clear bad energy, and flush away any bad spirits."

Even so it's use would still be frowned upon by most pub-based folk clubs in the UK, and most of them probably wouldn't get the idiom either. Otherwise my argument has always been that ALL music operates on the level of Shamanic healing - that's in the nature of music & accounts for its universality. In the English Tradition of Shamanic Healing Folk Song I would recommend Butter and Cheese and All as being particularly potent - especially when sung by the right sort of Shaman:

http://www.youtube.com/watch?v=sOx6fEYq8jI