Steve Huff Photo.
Now that I've read it again he does say that 'it will ruin the chems' and that he uses 'waste lab chems', so he's probably just doing it one-shot and ditching it so doesn't worry about contamination. If only we could all get waste-chems to play with....
Anyway, the only other option is Cinestill, which is removed pre-taking, which would add to halation (depending on whether that's actually what you want).
So yeah, taking then removing remjet then developing certainly makes the most sense to me too now.
Also, I just noticed Stone and Athiril said 'Sodium Bicarbonate' (NaHCO3), and the OP said Sodium Carbonate (Na2CO3). Maybe just a slight confusion of chemicals could be leading to these results?