Peter, it works best on panel. It is actually similar to what David Heskins does, called Mana Prima: he does it with powdered pigments on a panel that he keeps damp. There used to be a good process video by him, but he deleted it again (I should have downloaded it). There are a couple of videos by lesser artists, but not very good (i.e. disregard all the pseudo visionary mumbo-jumbo intro like incense burning etc ....) Mana Prima Technique (like, they don't know when to quit, lol).
The difference perhaps is that I use various erasers (and maybe fine grained sandpaper) when done, and the panel is dry, to work dark into light. So not like this video, where the background is dark. I do it on a white panel. I think David does as well.
Maybe I should come to your place sometime and we do a few of those. Your skills with the airbrush may just take this to the next level!