plug in earth products shouldn't be used in america or the uk?

The author in these videos says they should not be and backs it up with these tests.
http://www.youtube.com/watch?v=-sd3cGdBV1E

http://www.youtube.com/watch?v=LiKe1WMYNsM


His reasoning is that american houses are grounded in a way often causes stray voltage to leak into the grounding system.

The fact that his house just happened to have massive stray voltage in the ground and my buddies plug in grounding mat gave me so much discomfort i had to quit using it after 20 minutes tells me this happens very often and it not just isolated inscidents.

Does anybody have thoughts on this? Tweet