I carry a folder clipped to the inside of my pocket almost every day, and I
use it for all sorts of tasks. One thing that I've never thought of using
it for is self defense.
The reason for that is, is that I could never get it out of my pocket and
open fast enough for it to be effective.
You need to check out the Spyderco Waved Endura & Delica. They open as soon as it leaves your pocket, faster than a switchblade, & legal too. Only needs one hand to deploy it. There are vids demonstrating on YouTube. I have a waved Delica & I love it. I want to get a waved Endura now too.
I think that the Wave opening system is not allowed in Canada Andy, but I
could be wrong though and will check it out to make sure.
My Lapulapu on the top right (green handle) is legal to carry, and very easy to
pull from the pocket. You open it by brushing the flattened top part of the
thumb ramp, when closed, on your opponent's body. It has the effect of opening
and cutting in one move, and it works.
I stupidly tried it on my arm one day. Luckily I was wearing a thick leather
jacket at the time, but it sliced right through the sleeve.