Pretty much anyone over 40 doing a home video in their garage is going to come across like that. It's really unfortunate, but appearances do matter, a lot.
In this case, besides the appearances, what the guy is demonstrating in the videos seems legit.
Here's an earlier video where he explains what he believes is the effect at work, with a simple demonstration: https://youtu.be/I3g0CcLzC6I
It would be awesome if a youtuber like Steve Mould or Dustin from SmarterEveryDay did a video on this.