While the cosmology behind it all obviously cannot be valid, there is something to it. Over the course of thousands of years, why wouldn't they come up with something useful, even if they can't properly explain it?
A friend of my father's had a tumor in his throat. Western doctors tried everything they could and concluded there was nothing they could do and that he would probably die. He went to Beijing and sought out a renowned doctor of traditional Chinese medicine and after a few months it was reduced from the size of a golfball to the size of a pea.
One of my professors was from China, and he studied an obscure martial art for 16 or so years before becoming a professor. He believed in pretty much all of the superstition behind it, but whether it was true or not, a lot of it worked. He told us that if he started feeling sick, he would just meditate for an hour or two and it would go away (properly circulating his Chi). One day in class he had a bad cold, sneezing a lot and coughing. I came back a few hours later to turn in a paper and he was completely better, tip-top shape.
There is something behind it, I will tell you that. It's just so different from western medicine that it could take a while before it is properly evaluated.
