LOL…I love the key technique…can you seriously imagine a girl coming at you with a key, in the event that you were attacking her?
Stun guns (handheld non-firing) are weak, my mother had one one when I was a kid and me and a few friends used to zap each other with it - the sound they make is supposed to really be the deterrent. We played with a few different models in police academy which were fun but not the best for defense.
An actual projectile firing stun gun is an EXCELLENT form of self-defense. I carried one of these for less-lethal force as a law enforcement officer but don’t recall civilian law on the use of one. I have yet to encounter someone who could resist this method. :bigthumb:
My personal experience for womens self defense weapon would definitely be Oleoresin Capsicum Aerosol. There are 2 key points to this stuff.
1.)Don’t buy it at target/walmart/online ect… Go to a law enforcement store such as Markel’s on north side and pick some up. It will be the highest percentage and most effective.
2.)PRACTICE! If you have never been pepper sprayed or around it it is sickening. The weaker formulas aren’t nearly as effective as law enforcement grades - which are available to the public. I would always recommend spraying your female partner with it so she can feel the effects and know 2 things:
a.)What effect it will have on the attacker
b.)What effect it will have on herself (overspray)
-The spray will be much easier to keep in her purse and less legal consequences and hassles if used. The effects will be substantially raw for the attacker and she may even get a good kick to the face before she retreats. 
*The pepper foam is what I like more as the overspray is not as bad. The only downfall to the foam is you SHOULD shake it before use and it has a shorter shelf life than liquid.