What is the scientific explanation for how the handkerchief worked to deceive the Nazi soldiers?

From the text:

"It was Peter who took the problem to scientists and doctors. Some very fine minds have worked night and day, trying to find a solution.
"And they have created a special drug. I don't know what it is. But it was in the handkerchief. It attracts the dogs, but when they sniff at it, it ruins their sense of smell. Imagine that!"
Annemarie remembered how the dogs had lunged at the handkerchief, smelled it, and then turned away.

the handkerchief has a smell that disturbs the nose's of that of people and animals.