Is it possible that some of the "Quakery" medicine and treatment of ailments such as AIDS and Cancer could be.?

Skepdoc's answer once again is spot-on. Also, keep in mind that the bulk of "quackery" today is downright scams, with no plausibility and that do not beat placebo when subjected to numerous clinical trials. Skeptical evaluation and scientific method is crucial to weed out the rubbish. Peoples lives are at risk. Good question, by the way.