You could also insulate grids. Maybe with delrin, even ;-) I'm 100% serious.
It's the "recreating lightning" method. Though the main way is slamming HV discharge, the air ions charge on dielectric coating may have a role too. Recall that Tesla said that radiant energy could create charge in metal or if not - discharge any charge from metal.
So the first stage would be the beginning of arc which also create ions and negatively charge inner grid by induction. When slamming occur that charge may be speed up to ground adding to the cold electricity current amount.

Just an idea.Radiant energy is surely magnetic flux but the resulting cold electricity may be just HF high current, who knows.

The slamming you described is an effect of magnetic reconnection phenomena and require plasma and unidirectional flow of current inside plasma.
I'm quite sure you cannot get it to work using transistors.Even with normal arc it's rare because there is oscillation inside plasma , no unidirectional current so magnetic filed lines are oscillating too and energy is dissipated by EM waves and heat.
It's also a positive feedback example.

Magnetic Reconnection: MHD Theory ... - Google Book Search