I think there are many anecdotes that prime has helped in emergencies, though it does not actually seem to lower free ammonia (which is the toxic form). Unless I had an extreme emergency with no possibility to do a water change I personally would not rely on it. (i.e. a water change would be immediately effective ). .As someone else said - the only way to tell if it 'detoxifies' ammonia would be to do the experiment - which I do not think anyone is willing to do. There was one done with amphipods, but IMHO, there were methodologic issues with that experiment.My understanding is that Prime "detoxifies" ammonia by converting it to ammonium which is much less harmful giving system time to process it. I haven't read through the attached links yet but don't most test kits measure total ammonia which would make it difficult to analyze?
Coming from the fresh side I've used Prime extensively, mostly for de-chlorinating properties, and while I've not conducted any studies I've got a lot of anecdotal evidence of it being beneficial in an emergency. Very interesting topic.
I've not used Prime for my saltwater tank and don't really see a need to though I guess if I had an ammonia emergency I would probably reach for it in combination with water changes.