I think that one can get a stable arc by using a
circulating pump to power a water jet immersed below
the water pool surface squirting water from a nozzle onto the anode.
The dish sprayer at the kitchen sink held beneath the surface
of water in a pan shows that the jets emerge intact when
pointed upward.
Borax and/or Baking Soda should get the conductivity
up enough to run off 24 volts or so DC, if the area of the jet
is sufficient.
