Does spraying bug repellent (etc.) into a lighter really work?

I've heard stories about how crazy people get a lighter and spray a liquid somewhere along the lines of bug repellent etc. to make a flamethrower. No, I am not going to try it, but it's just something I was wondering about. It sounds like it really does work, spraying flammable liquids into a flame. So if it does work, what liquid is best and how far do the flames reach?