Well, before, my oscillator/transformer stage was behaving a bit wimpy and only dishing out the juice at around 230-250V. So, I put the doubler in there to get it up nice and high. But now, it seems that I don't need it to do the job. You can see the sort of setup I was using before in this short and slightly childish (but fun to make) video:
It took an ungodly amount of time to reach full charge, only going at a few volts per second ¬___¬