If or not specific dogs are capable of detecting specific chemicals in specific environments is debatable. However, dogs and other trace chemical detection methods have an immense advantage over whole body scans: they are the correct methodological approach.

Body scans start out all wrong. They will detect objects on the surface of bodies. They will not detect anything inside bodies (therefore leading to a serious loophole of a false negative) and cannot distinguish between benign (the vast majority) and suspicious items, leading to a boatload of false positives and passenger harassment.

On the other hand, trace detection is designed to detect traces of dangerous chemicals, no matter where they are. Beginning on this premise and working on specificity and sensitivity is the proper approach to the problem at hand.