What about sand? Or talcum powder. I think the concern is less about cleanliness or hazard, and more about finding a rational, normative basis for seeing someth

What about sand? Or talcum powder. I think the concern is less about cleanliness or hazard, and more about finding a rational, normative basis for seeing something unusual on an X-ray. Questionable items with no obvious cash value simply go away. Off the plane. It probably is the smell, the charcoal and trace chemicals that mess with swabs and dogs.