Yeah I can't quite understand how you do it with your index finger, I use the side of my thumb that hangs over the side of the pick. When I first tried to learn I had the strangest instruction ever, I was watching the Vivian Campbell instructional video back in 1990 or something and he said you just turn your pick on the side, a 90 degree rotation and pick down, this wasn't very helpful and I had to go to my local guitar shop and ask in there instead! Having said that that would probably be using your index finger for the P.H.?