Isn't disappearing effect just scaling"
Yeah, but what I didnt know was how to control it - [When it should start disappearing/How long should it take to finish disappearing, Which ones should even disappear at all, etc.]
He also uses the animation and deformation of instanced object/poly, doesn't he?"
Yeah, he's doing keyframe animation transfer and he's baking down the effected objects, both limiting factors IMO. You can keep it all live with ICE and add some randomness to the effect, e.g., each object/poly doesnt have to do the same thing, in the same way. With his current approach, that's not possible. Granted the man is obviously gifted, so he's probably not done working his magic, but ICE as a platform, offers more flexibility IMO.