Another way to do the fracture cell makes sense would be to have exactly what he shows for generating the high voltages but to connect the inner plates in a parallel resonant circuit and drive it at the resonant frequency.
The beauty of this circuit is that it works like a Van de Graff charge bucket if you add charge when the potential is zero you can aways add charge analogous to charge from inside. one side charge pull the other.
at least is what i'm seeing please tell me i'm wrong.