I mean, in your case than the electrical stress remained mostly into the spark gap not on water!
I'm not sure if its the correct term but when i mean across i mean you could see or measure the high voltage applied at the cell poles.
I'm pretty inclined to believe that meyer had some secrete inside its inner tube!! Probably also in the construction of the resonant cavity!
The idea is that to apply a high electric potential to the water you need big charge and yet the insulating material should have high resistance, dielectric strength, and dielectric constant, than water for the system proposed.
Meyer indeed told us the secrete is to restrict the amps
He was really smart since he just mentioned it and never provided the background necessary for this subject to be understandable.
Of course it was so simple and stupid that he could not reveal this or his patents would be useless.