In the current Fly Rod and Reel there is an article about wool flies. The author discusses using raw wool for hackle–since it still has lanolin on it, it doesn’t absorb water and floats. I like the way it looks, and have tried to get a similar look with other materials without much luck. I never tried wool because I assumed it would sink.
I haven’t seen the article you mention (I don’t get out much) but I’ve only used wool on flies I wanted to sink. Having just washed a couple of fleeces, I’d say that wool does absorb water, even with a significant amount of lanolin in it. I’ll have to go find the magazine and see what they’re talking about. Maybe the trick is in the method more than the material.