Those are inferior choices that are not meant to be held along with you. Plus, you don't need to go out and kill someone in any case. Instead, what you would like is a defensive solution, and that is certainly where non lethal self-defense weapons enter into action. These are generally robust solutions that can help keep you safe and sound always.
You are going to put them into your bag or in your pocket while knowing everything will work out in your favor. These are a great solution to suit your needs.