I think I disagree. This type of practice (AND practice swing on the course) IMHO, is more about gaining the all-important feel for the head WITH proper location of the hands. The first step with practice stick at home or driving range. Second step with practice swing at practice or on the course. AND one more for a good "waggle."

Waggle is defined as "the bridge between the address and the actual start of the backswing." (Ben Hogan, Five Lessons, 1957, p 65) "Possibly because the word waggle suggests any aimless kind of oscillation fills the bill, many golfers have the mistaken idea that it doesn't really matter how you waggle the club - that the only purpose is to loosen yourself up. There's a great deal more to the waggle than that. It is an extremely important part of shotmaking. The shoulders do not turn. The feet make only small adjusting movements. The hands and arms move. Preparing for the needed path and the tempo for the wind and lie. The waggle, in other words, fits the shot." I think we are all very familiar with the near religious pre-bat routine of baseball players. This seems a good way to develop a proper waggle.

Watch Ben Hogan spend far more time looking at the ball than the target (now, I would move the arms more, like the half swing done in this Golfpass video):
https://youtu.be/JlEtR6WoEfg?t=34

Watch JD Martinez looking at home plate, not the pitcher, to get ready (when golfers look up and see they can't hit, they wait, instead starting the routine from start):
https://youtu.be/fu5a9GAb0WA?t=44

Phil Mickelson's pre-shot routine starts behind but he also looks at the ball:
https://youtu.be/UAY5tvlLIbQ?t=23

Preparing for a backswing with your hands (such as in a waggle), arms, shoulders, hips - reversing the order for the downswing. "In the waggle, the left hand is the controlling hand," says Hogan. Bob Toski writes in confirmation of the importance of a good waggle before swinging. David Leadbetter prefers students begin with a gentle motion a foot ahead of the ball. Then, Phil's "Hinge and Hold" is like baseball's fence drill (using the ground as the fence): youtu.be/Oi7BkBF4mGg

I thought that the type of putter determined the swing path. Face balanced for pendulum, toe heel weighted for swinging door. Is this true?

Nice visual there with the alignment sticks!

Keeping everything lined up is key! Thanks Devan!

Nice drill

I like how he teaches.