Hudson Hi-Fi provides no proof that the goats hair bristles of their anti-static arm "discharges" the negative charge on the surface of the LP (or even a technical explanation of how that discharging is accomplished), transfers "something" into the arm, and then into a ground wire, and that signal in the wire is then sent to ground. Color me dubious.
The static charge is a very well understood phenomenon, as is the means required to neutralize it. Anti-static brushes have been in use in film labs for decades. I see no technology in the Hudson Arm that seriously addresses the static charge. The Arm looks like a toy to me.