Makes no difference. If it "makes the dog sit down" you get a closer look, as will your shoes/sneakers/clothing AND luggage.
This happened to me. I used a bag that I had previously had used to carry some handguns (freshly shot) and about 50 spent cartridges. They were not in the bag but some of their residue was. I seem to remember some lady rubbing a device on the zipper and the zipper pull and got an alert. They went through the bag and I was on my way. All before 9/11.
If some lady rubs a device on my zipper I might give off an alert too! LOL