ptygmit, the placebo effect is totally disproved, as far as homoeopathy is concerned. It works equally well on:
animals, included in their feed, for otherwise fatal conditions such as lantana poisoning babies, people in a coma, people slipped a remedy in their sleep, total and utter skeptics, curing things people had forgotten was wrong with them.
Anyway, in my opinion, if a placebo cures 90% of the time (which is my experience over hundreds of patients), then it's such a good placebo that its use should be supported, rather than denigrated.