Before western medicine, the field medicine was the accumulated knowledge passed down through master and disciple, or mother and daughter (father and son.)
Even the most passionate, anti ‘vodoo’ magic Tongan will have to suffer the reality that you’re going to have to drink that ‘black’ magic medicine or have it rubbed over your skin. It’s just part of the every day life of people although Tonga has generous medical services, it can’t afford everything for everybody.
And you know what? some of the stuff works, well enough.
For a review of the culture and tradition of the medicine
From the Ha’apai clan we have some immediate application, less discussion on the theory.