This is an overly complex plot with little reward except to try to fool kids into opening booby trapped lunch boxes when you could simply leave out all the duds and only place bombs near the kids. The concept that we should treat each and every one of 100 seemingly identical items as if this one was dangerously different is a collosal waste of resources, especially when entirely more likely explanations for the composition of these items exist.

Garbage cans have been known to house bombs before, should we investigate each garbage can as if it may blow up?