I think I would be worried about damaging my keys. Can't replace an organ as easily as a keyboard.
Also notice that when he does his 'Smear' he curls his fingers right back so he is 'smearing' with the
palm of his hand. My fingers can't do that (bit of arthritis?) and they curl forwards, not backwards so they get in the way.
Hugh
PS. Brian's 'Glissando' (the official term for a 'Rake') looks more to the point and fairly easy to do. Funny how when you watch somebody doing something it always looks easy until you try and do it yourself!
viewtopic.php?f=2&t=5725#p37584