Mishpacha wrote a feature article positively covering the book, and then issued a retraction of sorts, after receiving many critical comments from rabbis about the field.
Apparently, some rabbis, like R’ Szmerla, argue that nearly all alternative medicine and associated practices like energy healing are permitted, while some, like R’ Belsky, forbid many of them, particularly things like energy healing.
I would stay far away from reiki and energy healing and such, but traditional forms of medicine like Chinese medicine (which involves not just acupuncture, but also herbs, exercises like tai chi or qigong, and other practices like massage) would seem to be unproblematic, and in practice, are openly used by well-known rabbis.