Hi yellowflowers
responding to your last bump!
I have read the same thing as you on various sites. My conclusion (i'm no expert though!) is that it is probably not bunkum. This study content.nejm.org/cgi/content/abstract/340/17/1314 showed that DCI improves insulin sensitivity, decreases androgens/testosterone and therefore helps most PCOS women to ovulate. DCI is also mentioned in The PCOS Diet Book by Collette Harris, which as far as I can tell is quite reliable and well researched.
The problem is that it's quite hard to get hold of DCI as a supplement. DCI or Pinitol (which is apparently converted to DCI in the body) is available from one or two companies in the US but the price tag is absolutely enormous.
Buckwheat does contain DCI, the best source is the farinetta (84mg per 100g) but that seems to be equally difficult to get hold of in the UK and very expensive. Ordinary buckwheat grains however are available from health food shops and sometimes even in supermarkets - I have been trying to integrate it into my diet. To cook buckwheat you just dry fry the grains for a couple of mins (optional, improves flavour) then boil just like rice or couscous for about 10 mins. The taste ok.
The problem is that there is only about 23mg DCI per 100g buckwheat - and the study that showed results involved supplementing with 1200mg DCI daily!!! So it's difficult to get enough of it without eating excessive carbs. Other sources of DCI and pinitol, according to my research (again, I've probably been looking at similar sites to you) include soy lecithin, carob, mung beans, aduki beans, soy beans and chick peas. I tried eating the requisite amount of carob but it was impossible - I like carob - but if you can imagine just eating an entire jar of cocoa powder in one sitting, it was like that! intolerable. As far as I can tell you'd have to literally live on a combination of all these sources to get any benefit so personally I'm feeling a bit despondent about it. It's very frustrating that the DCI supplements are not more widely available.
You can also try supplementing with ordinary inositol which is available in UK health food shops in powder form. That works for some PCOS women but not all. I am currently trying it as part of a low GI diet - so far my skin has improved but no ovulation as yet, am only into the 4th week of this regime though.
Do you have a copy of the PCOS diet book? I would recommend it, it goes through all the supplements and herbs systematically and explains how they can help and any contraindications. It requires a little patience but it's useful to have all that information in one place.
Sorry for the mammoth post but I hope that's useful.