I’ve heard of this years ago, and I teach basic electrical theory. I’m not an expert in electrical static discharge, and I can’t validate his work, but I can give my “dummy english” explanation of what I think he’s doing.
I’m hoping everyone here has rubbed a balloon and felt their hair stand up. Static charge can build up on an object, positive or negative, and they will repel like charges, which you’ve also probably done with a balloon. My understanding is they build massive repelling charges on the same fixed object, and off-balance them so electrostatically, compared to the local frame of reference, the object is impelled in one direction. Electrostatics at small scale can obviously defy gravity (ever pick a charged piece of styrofoam off your shirt?), but scaling and exceeding the frame of reference have always been the failing points. You can build huge potential to move with charge, but you need something to move against, in general. The charged styrofoam needs you to move your shirt to move in the previous example.