I have heard of this, but bark doesn't seem to work well long term in my conditions. My philosophy is that there is no miracle medium that is going to work wonders in every person's growing conditions. If bark works well for you, you might give it a try on a few plants and see what happens. I did that with Aussie Gold on my Paphs. I read reviews on it and there was both good and bad. The company of course claims it will solve all the world's problems (or at least those involving growing orchids ). The few plants that I experimented did well, and in fact, my Paph. fairrieanum loves the stuff and is going absolutely crazy. You should see all the roots . I have since potted the majority of my Paphs in that mix and they seem to be doing well, at least so far.