Hmm... I do empty lung (but not reverse packing) dives in our local pool (-5m) but still make the funny noises, they don't seem any more difficult to clear my ears than full lung dives.
Though now everybody can tell if I am diving, I always show up for practice late for practice and make the funny noises.
I still wonder if you are right that I am not fully closing off the epiglottis.
