Calling it "snake oilish" w/o justification is a bit harsh and unjustified. It's not like I'm talking about waving a rhino horn over one's head. Anyway, I make no dramatic claims (or any, really) and in fact applaud a healthy skepticism - the key word being "healthy." ie taken too far, that can lead to a closed mind, which is as dangerous as one that's too open. Sorry don't have links offhand but will investigate. Don't buy that hot tub just yet.
Edit: here are a number of links, admittedly most of which I haven't read yet.....
http://www.bsdmc.com/search.html?search_term=Prostate+Cancer+Therapy (http://www.bsdmc.com/press.html?id=357 - broken link)
Also here is a "generic" explanation of the concept:
http://images.olwm.com/bsdmedical/pdf/hyperthermia.pdf (broken link)
(http://www.bsdmc.com/press.html?id=357 - broken link)