It is really good, and I really hope it gets published someday. I just finished it, so I'm not quite ready for a review. This I'll say, it makes an enormous number of connections between gongfu and popular Daoist ritual cults to various martial deities.
Just briefly, the inner circle of these exorcistic cults are sworn brotherhoods, gangsters if you will. They are all into gongfu, and gongfu deeply informs their trance/possession routines. Some of them claim historic roots in local militias too.
One cool part of the book deals with a particular ritual called Handan Ye. In this ritual a prominent gangster is carried around on a sedan chair by other gangsters. The locals line the streets and throw firecrackers at them. The gangster is allowed to wear goggles and shorts, but that is it. He is in trance the whole time, possessed by a god. When it is over he is covered from head to foot in burns.
It seems like this it a chance for the locals to help him clean up his demerits in the Book of Life, while getting even with him for terrorizing the community. This raises a lot of questions, which I shall go into later, but I think it is worth saying that this is an extreme form of martial conditioning. It demonstrates actual prowess and creates a theatrical performance image of extraordinary potency and danger.
Watch it on Youtube!