More effective than a 'stun gun'? Absolutely.

More effective than a taser? Eh, there's some give and take there, and it probably depends on the circumstances.

• Tasers only get one shot before needing to be reloaded, so aim is much more crucial than pepper spray, which can be, well, sprayed.

• Some people seem to have a natural resistance to pepper spray, making it less effective on them. It may also be less effective on someone under the influence of certain drugs, or even just someone wearing glasses.

• Pepper spray has less range, requiring you to be much closer to your attacker. (It can have especially low range if the wind is against you.)

• The effects of pepper spray can be longer-lasting than a taser (at least the typical civilian model of taser). Civilian model tasers will stop shocking after a set time and won't allow you to continuously re-shock the target like police model tasers do. While pepper spray will generally last quite a while, until the target can wash it away. (Though, in either case, it should be enough time to get yourself out of the situation.)

• There's more chance of accidentally spraying yourself as well with pepper spray, especially if it's windy or in a confined space. (Whereas, unless you're really bad at using it, you're probably not going to shoot yourself with a taser.)

• A taser can only work on one target at a time. If you're attacked by multiple people, you can only target one of them. (While pepper spray can easily be split between multiple targets if necessary.)

• Pepper spray is better at being non-lethal, with it being extremely unlikely to cause death or even permanent injury. Tasers, though, always come with some amount of risk -- if used on someone with cardiac issues, they can be deadly. And there's always a chance it could cause the target to fall over and hit their head or something.

There's pros and cons to either side on that one, and I think either one (or even both) is a reasonable choice. (A couple more pros of pepper spray not related to its effectiveness is that it's cheaper, smaller, and easier to carry.) When it comes to that choice, I'd recommend just going with whichever you're more comfortable with. But still -- please practice using it, at least once! No matter what you choose, it will be much more effective if you have experience using it and know what to expect.

I could see it, but if we're going with hand-held weapons... Icepick. 😉