At the Wilderness Survival (St. John Ambulance) camp we did last year, we brought 6 FRS radios. The first day, yeah, everybody was yaking away wasting bandwidth. But our reason for bringing them was to teach the Radio Proficiency (proficiency = BSA Merit Badge). With very little instruction (and a clear acceptable use policy laid out), we combined this with a map-reading exercise, where cadets were required to report in every time they reached one of their objectives. For that exercise, at least, they exhibited very good radio discipline and etiquette. Partly due to the fact that they'd "gotten it out of their systems" the day before by playing around with the FRS units, and partly because they were given a specific tasking for the radios, so they knew when to speak and when not to speak.

If the radios are being used for a specific purpose (teaching or otherwise) I don't think there should be a problem; the real problem is giving them "toys" with no instructions on when, where, how and why to use them.

There are no bad hammers, only bad carpenters ;-)