I agree that's better to take steps backward, if it even does for them, then to take risks of serious injuries or even death. I know it means re-cleaning everything again, but that could just mean completely cleaning everything at once instead of in parts. I don't know your work schedule, but you could try to figure what will work best and you would have the most time for an all-nighter for maybe 2 nights at least. Then during the week within a few day before your all-nighter, try the intros as suggested, while they're sleepy, and see if they sleep nicely in pouch for the entire day.
Also, when separating them, keep the pouch swapping going, and maybe some toys as well so more of each others scent is in their cages. Then, when you feel safe leaving them unsupervised, you'll realize how worthwhile the steps taken back were.
It's up to you, I'm just suggesting what i would do in this situation, always "better safe than sorry"