Yesss! The lightning choke! An idea that even has intuitive appeal to
me, and I have already gotten some pipes to wind one on (and weatherize
it too).

Even w/o a dedicated grounding on the "cold" side, it has the effect of
slowing the rise and giving the spark gap more time to work on the bolt
energy.

Chokes are even available commercially, and are used a lot in animal
concentration camps (well, make that on electrified cattle fences).

See
http://www.kencove.com/ShopDetail.php?recordID=MWLA
and
http://www.kencove.com/ShopDetail.php?recordID=MLC.

Now off to buy some CRT high voltage wire for the DC grounding / DC
block wideband transformer.