Even if that did calm them down and they seem fine, when I add them to the display tank I would be introducing them with some sort of parasite wouldn't I ?

It could be the treatments actually irritating the fish and not parasites. Which is why the hyposalinity seems to be a better option. I am by no means an expert in quarantine but I would do a massive water change and switch to hyposalinity for a period of time and observe.

when i first noticed the flashing yesterday i also noticed the water was a little cloudy looking , which it has never been like that before.I did about a 70% water change last night and I haven't seen any flashing or rubbing today. No ammonia or nitrites and nitrates are 0.2 When I was doing a water change last night I found a pile of un eaten food that was hidden behind one of the PVC tubes ,I syphoned it all out last night. I'm really not sure what to do , the water still seems a little cloudy today , but the fish seem fine.

Just noticed the royal gramma rubbing against the PVC tubes.

She also didn't eat when I just fed them , I guess that could be from the prazipro treatment that they just finished though , since it can suppress the appetite.