Among the many cinematic details of the prison-break story is the fact that police found a pepper shaker at the escaped inmates’ campsite. The pepper, state police believe, was likely used in an attempt to throw the police dogs off the inmates’ scent — like in Cool Hand Luke — and state police superintendent Joseph D’Amico thinks it might’ve worked. “We did have difficulty tracking, so it was fairly effective in that respect,” he said.
Except that’s probably not at all what happened, said Pamela Dalton, a cognitive psychologist at the Monell Chemical Senses Center, who studies environmental odors. “I doubt it had any effect at all,” Dalton said in an email to Science of Us. “Bloodhounds and other scent-tracking dogs are able to isolate the to-be-tracked body odor among the myriad of scents that are found in the natural environment.” Alexandra Horowitz, director of the Dog Cognition Lab at Barnard College, also told as much to the New York Times. “There is no way that people can erase the olfactory information that they are leaving when they move through space and touch things in the world,” Horowitz said. “The dog is more effective than the escapees’ attempt to elude the dog.”
Pepper is, of course, an irritant, and so it might’ve caused the dogs to sneeze, which may have stopped them for a moment — but this “may actually have served to clear or refresh their noses,” Dalton further explained.”The escapees obviously did not see the episode of Mythbusters where they tested this idea and disproved it.”