Costas,
I have not seen your GY fig thread yet, but let me explain this better.
I root all of my cuttings directly in the potting medium (P.M) that I use. I don't use baggy method or any other methods. So when I have a large cutting (10+ inches long, 2-3 inches in diameter), before placing the cutting in my P.M. I scrap the bark off in three or four places around the base of the cutting, then it goes in the P.M.
I do the same for air layering too. Some pics of my recent air layered branch for you to enjoy.
Navid.