Watched the video, and watched the follow-up video where he's trying to reason out why someone has told him he's wrong when he says it doesn't matter which wire from the dummy pickup goes to the switch and which goes to the volume pot. I then read through a bunch of the comments to the second video.
A number of commenters point out that he's completely missing the point that the dummy is a coil, and that phase and polarity need to be considered. On the other hand, he says there's no hum; and other commenters have said they've done the same mod and it works.
One commenter said that you would need a switch to reverse the dummy to use it with the middle pickup, and a switch to turn the dummy off when in the second and fourth positions.
Interesting.