I watched a video yesterday and a guy measured the resistance of his spark plug wires to 11,400 ohms. That is pretty close to Stan's 11,600 ohms for the chokes, looks like impedance matching going on here. Does that sound on track to you?
Thats part of what makes it work. Otherwise you will cook the blocking diode and melt the solder. Just high voltage as you traditionally think of it as, won't do it either, because that won't break down the water. Its how the voltage is made.
My setup will arc at about .002, I need to get it to arc at about .008 and set the gap to .010 so it will make the gasses fast enough to explode. At .002 it will break the water appart to the point where it smokes and vaporizes the water to where there is no trace of it left. You can see the gas coming off of it. If its broken down fast enough at a high molecular level it will explode.
Best way to describe it is burning water.