In her (more recent) performance here:
I get the impression/idea that she's playing the passage by playing two "standard" arpeggios in each hand, split a step apart. I don't think that's what she's actually doing, but it gave me the idea. I've written out the sheet music:
which you can play here: https://flat.io/score/613afd2d4bad330012efceca-prok-3-glissando. This is still quite difficult, but I think it is easier (personally) than the "play two keys with one finger" strategy that seems to be "standard".