I have had people take hyperbaric oxygen therapy for foot ulcers with some success, but otherwise had no idea these things were being used to treat cancer, AIDS, and other illnesses.  The Cochrane Review looks to be gearing up to review the use of ozone in diabetic foot ulcers soon, stay tuned for some of their usually definitive coverage. 

Doctors purveying questionable therapies: if you're not careful, the FDA will sic the US Marshals on you!