I did watch a bit of the video and did see the point where Mike is doing the step potential test with himself as the meter. I saw him say "I'll let you know when I feel it". That was over my limit.
I did want to see the actual hands on of how they floated the equipotential grid, and then connected the 120, and especially with a clamp on Amp meter on the power source because even floating I am pretty sure there was still some current flow (to earth and then to the system bonding jumper). Unless they also floated the system bonding jumper, and if so, I would say "A good magician never reveals his secrets".
If the source 120 had a system bonding jumper, even floating the grid will still give some current flow, but maybe not (through the pool water while someone is swimming in it). Floating the power source, then floating the grid, connecting the two and swimming in it, that's a magic trick.