Non-recognition aggression help!

My male cat Tony had a 48-hr visit to the emergency vet and he had to get a catheter etc. On his way home, he peed on the pee pad (under it was a blanket that had some pee on it from going to the vet) and when we left him in the carrier initially to get his litter box ready, we could hear the other cat, JJ, (female, same litter) hiss at him. I figured this was bc he was in the smelly carrier so we took him out, gave him a washing and let him rest in the bathroom overnight.

The next day, we decided it was OK to let him out but JJ started sniffing him and hissed and even started growling which I've never heard her do! After hissing and growling she lunged at him and chased him around. He hid under the bed and they ended up having a fight under the bed. He yelped a few times, so I was worried that he was getting hurt and tried to lure one out from under the bed. We ultimately decided to put Tony back in the bathroom and have been separating them for the last day and half (it'll be 48 hrs upon his return this evening). Tony is already on gabapentin and JJ is on pregabalin while they're getting adjusted to the lyrica for their general stress and inter-cat aggression before this incident (where Tony was typically the instigator).

Other than separating we have also tried:

- Swapping blankets each of them are using so that they get each other's scent on the blankets

- I'm petting Tony with my hand that has a fabric brace on it, hoping it gets his smells on it and then I'll have JJ smell it and pet her with it

- I've even brushed Tony and taken his hair and brought it to JJ to smell. She licks it and tries to eat it lol.

After almost 2 days, JJ is still hesitant to get too close to the closed bathroom door. Yesterday she growled while I gave her a churu outside the door. Today she didn't growl but quickly squirmed away even though she loves churu.

Does anyone have tips on re-introduction? How long could something like this take?