I can't speak for all the rest of the machines but I can certainly say that the DOUG COIL machine does in fact work. It is a very powerful machine. I am sucessfully treating lyme, morgellons, parasites and mycoplasma. Yes it works and I can absolutely tell when I get a hit and have a herx. My goodness, with parasites you usualy get a visual when you are killing the pathogens.
It would be a shame for someone that needs one of these machines to not get one based on that statement that they don't work. Maybe they don't all work but the doug coil does. Research it and see.