Someone suggested German Shepherds. Great idea. You can’t fool the sniffers on those puppies.
You don't have to be a German Shepherd to smell a Muslim approaching.
You are correct, I was in Baghdad a couple of years ago and heard the story about a dog who had sniffed out a bomb in the tank of a full sewage truck that was used to clean out portable toilets. I would not want to be the guy who had to recover that one.