Faux Pas Part Deux

I posted the other day on the "French Explosives Left in an Unsuspecting Passengers Suitcase" story. And I've been thinking:

PARIS - Somewhere in the world, there's a navy blue suitcase with a small pack of explosives tucked in its side pocket.

Four days after police at Charles de Gaulle Airport slipped plastic explosives into a random passenger's bag as part of an exercise for sniffer dogs, it is still missing — and authorities are stumped and embarrassed.

This stuff could be anywhere. So Here's a question: Doesn't this practice of temporarily planting explosives in passengers' bags leave residue on innocent person's bags that may be picked up by security the next time these people travel? Every time security swabs a bag and runs it through the instant analyzer, this is what it is suppose to catch, is it not?

Points to ponder...You gotta love the French...