The sceptics as a group have always opposed people attempting to promote a belief or practice without scientific basis. When they found an egregious case of unscientific mumbo-jumbo they would exclaim Wooooo! It was the kind of noise you made when there was some sudden and spectacular magical event, like a ghost appearing or something spontaneously combusting.
From this exclamation, shared in the sceptic community, we may get the word woo, the name for an outrageous piece of totally unbelievable pseudoscience. Sometimes it is referred to as a woo-woo. Reduplication always gives extra oomph to a word.
A woo-meister is someone who is particularly adept at pseudoscientific explanations.
Woos typically appear to be simple solutions to a difficult problems. A woo-meister wraps up the belief in scientific jargon while at the same time despising all the rules of science such as experiments which can be repeated, relying on anecdotal accounts in preference to hard evidence. The woo-meister feels that he or she is being abused and ill-treated by the scientific community. In the same breath they will call on some authority to confirm what they are saying, again relying on supposed reporting of what the authority had to say. The correct response is still Wooooooo!