Many modern drugs have unknown mechanism also. But there are other issues involved here.Technical and ethical issues which further compounded with historical traditions in T.C.M. practice. Hard to explain in short. The composition of this one is rather easier to figure out comparing to many other herbal formula. I believe there are studies done on this one in China which I would love to see more in detail in the future.(some mentioned its bactericidal or may be bacteriostatic effect) The key is no matter how magical an anecdote may seems like, the truth could only be revealed by rigorous scrutiny of science. If in facto the powder works as it is legendarily claimed to be, then it can be really a 福祉 as Mr. Wang mentioned.