Cops told my friend to carry cans of oven cleaner in her car. She was traveling often & in nasty areas. Said it will do a hurting on the face. I don’t know if it works as I am not trying it. I live by these rules, don’t put yourself in places where you shouldn’t be. Don’t get drunk & walk out of a bar, shop with a friend & don’t be an easy target. Fight back & scream, bite, kick, etc. Never use stairways because they are places that people can hide in. Ask somebody to walk you to your car if its late. And every room in my house has some weapon in it. You wouldn’t know what it is or where it is but I do. If my gut tells me to get out of a place I do. I always trust my gut feeling. As for a knife. I carry a buck knife all the time on the farm. Its sharp & handy. However I do not count on it as being able to save me. The shovels,metal muck rakes, axes & etc in my barn & the Great Pyrenees are my best hope.