Yes, that's a good idea. I have sort of been doing that. I tested first with about 80v worth of cells (shooting for 330v at the end) and then added a few batteries and got up to around 100V. Once that testing went ok I went right up to rectified 230VAC (the caps charged up to about 339V). Maybe that was too big of a jump.
Also, trying to run on rectified AC causes issues with the sagging voltage from the mains so I wasn't helping myself there either. So, maybe I should stick with batteries and just gather up more of them and add them a few at a time until I get up to a reasonable voltage.