I carry a pocket-sized OC spray in my primary hand pocket, top-down with a pocket clip on the bottom, oriented in such a way that I can quickly draw it with my thumb on the button in a clenched fist. I have also practiced with inert canisters, as well as a few expiring live canisters, and caught some blowback in the face in windy conditions, so I have an idea what that's like. I haven't ever needed to use it on anyone to say how effective it was or wasn't, but I have seen and read plenty of examples of both types of outcomes.
I would only reach for it in a situation where I needed to quickly escape from someone who was physically threatening me, but not with lethal force, and not up close, like some unarmed intoxicated or mentally ill person on the street physically coming at me and verbally threatening but still at some distance, as something I would do before ex. preparing to throw a punch or kick etc. Basically to temporarily blind and disorient them and then turn and run like hell. It's also something I would never use to demand compliance... I'd only pull it out and use it with an element of surprise.
Giving weapons to loved ones for self-defense is problematic unless they are already proficient with them, or you plan to get them trained to use it.
I would recommend against using wasp spray for self-defense. I've used plenty of it on wasps and a few other insects, but I have heard and read that against a human aggressor, it would not be considered non-lethal force and could be considered aggravated assault, since it could lead to permanent injury... it would only be justified to use against a similar threat. In other words, if you feel justified to use wasp spray, go ahead and draw your pistol instead.