Wow.. I don't know, but I did used to use molly fry to vary my seahorses' diet. Hm.. You could even do something with monos, datanoids or scats (though I think they're more of an estuarine/mangrove type of fish).
Did it years ago in order to feed seahorses (way before frozen foods) and it worked well, but I don't think it would benefit coral all that much. The fry tended to hide until they were big enough to maneuver, which means they wouldn't get blown into the LPS by the currents.