if the teens brought their own out of date epi pens, (as long as they had in date replacements on them ) they could use them on a orange , for practice and demonstration purposes.
in a group you dont need many to do the orange thing, just watching and listening to the click is enough to support learning, confidance and remove any fears about needles etc.
having heard from adults with allergy , who are not given or used the epi pen correctly the first time, such forward thinking is required. (one man told me he had been stabbed in the wallet in his jeans pocket by his wife when he had a severe allergic reaction!)
while i wont be posting to this person, if , say, the anaphylaxis campaign asked for some out of date epi pens, i would send them.
i have used a out of date epi pen on oranges in front of a group of people and it is a good learning tool. the trainer epi pens have there place, and should be used in a rehearsal type practice,(body positioning, counting etc) so that the routine is stuck in your head.
a trainer epi pen should never, never be put in the same bag, packet, that contains real epi pens. when searching for the real thing , you dont want to use the trainer!