Interesting news bulletins from the inaccessible and costly north of the continent: to detect foreign intelligence agents, be on the lookout for people with bad hygiene. Not knowing (or wanting to know) the ways of espioneurs and espioneuses, I can't say if that's true or not, but I do know that locals often have a keen sense for the scent of a stranger, and that it's not infrequently expressed in these terms. Compare the first reactions of the 19th c. Japanese to the European visitors. Perhaps the suggestion was a pragmatic attempt to trigger that sort of awareness.