Does anyone have a better option for screening the cast once it alarms? Unwrapping it is a bad idea, but if it alarms the (notoriously over-inclusive ETD machine), what can the screeners do to rule out the presence of explosives? I don't like the conclusion of this story better than anyone who has posted in this thread, but I'm not sure I have a better solution that wouldn't allow a cast made of explosives to fly.
Maybe look for other chemical signatures for use with the ETD that are not found in common hand lotions and 100's of other common, perfectly harmless household products.