In the early 70s we used to do zero-speed autos in Hueys, but we kept zero all the way down, not diving like in the video.
Aim point is between your toes in the chin bubble, go through the normal flare height, and when your @rse takes a bite out of the seat cushion, you pull the collective. Amazingly effective. To make judging the "pull" height easier, one instructor suggested drilling a hole under the collective and poking a broom handle through. When the machine gets down to broomstick height, it automatically pushes the collective up! Simples! Tccchhkk!