Ball jar dating
The leyden jar is a very old design dating back to the late 1700's Its simply put a high voltage high capacity capacitor.
Built properly and treated like a loaded gun you too can make your own miniature lightning bolts.
Tape along the line you just spray the out side of the bucket with a few coats of contact cement.
I also resprayed the bottom over the metal and put on another coat for a little more do the side getting out all the wrinkles as you go along.
Now that you have built it simply connect the doorknob to a VDG and charge up!
For a big spark connect another door knob to a pole that is connected to the outside of the leyden jar. Im wondering to experiment with a coil in there to see if can perhaps pick up in a way to step down or achieve some other awesome effect that is not yet discovered.
So for high current I would suggest using sheet metal instead of foil.
Your problem isn't because of the high voltage, the aluminum foil was vaporized because you have used unrectified current and there is no way you can charge a capacitor with that since the pollarity is periodically changing, it will arc inside the capacitor and melt the connections. Good luck :)A rectifier would be helpful, but the capacitor is still charged in within a half cycle of the ac waveform, much like the tank capacitor in a spark gap tesla coil.