the problem with that whatstheharm website is it uses testimonials and case reports rather than evidence-based data or studies, which is exactly how homeopathy and the like popularize themselves.
the harm from "alternative" remedies is usually 1) people pursue them instead of modern medical care or 2) they involve crazy-ass infusions or other dangerous practices. it's a tight line to walk with patients who are into this stuff, since dismissing their beliefs can be taken personally and hurt your relationship with the patient (and further drive them away from seeking evidence-based help). i usually say something to the effect of "there's no scientific evidence showing that it works, so i can't recommend it to you. i would also be very careful, since the risks and side effects are also unknown. if you decide to try it, be careful." of course, if the patient says something like, "i want to be injected with bovine adrenal hormone," my response would be something more like, "no, no, no, no, no, no."