In other words, OC isn't enough to "turn an assailant away" anymore, let alone "in horror," and that in turn does not bode well for the effectiveness of less effective sprays.
I can vouch for this. In the course of my military training, I had to go through an OC qualifier course, and then 2 refreshers every two years or so. The first time I got the sauce it hurt like the damn dickens. Every time I got it thereafter, it was a little less painful once I learned to manage it. You can fight through the pain, and there are some folks it doesn't hit at all until a minute or so when the sweat takes it into their eyes. Stream placement is a big issue with OC. If you get the forehead, it's going to take a bit for it to have an effect. If you absolutely saturate your target, you're going to get some of the effects too. The other thing to remember is that OC, like any sort of defensive weapon, can be used against its operator. If your assailant is under the influence or one of those rare people that OC just doesn't do anything to, you're going to be screwed. Unfortunately most defensive weapons run into this problem as well. Stun guns and kubotan-style keychains require you to close the distance to your attacker. They're good when he's already on you, but in this case unarmed grappling and escape techniques are probably more effective. Tazers, firearms, and OC require the operator to be able to discharge the weapon accurately
under duress. As for me, I can put a 4-inch grouping at 25 yards with my FNP .40 on the range, but that's a heck of a lot different than a real encounter where I'm not going to be ready for it and probably really freaked out as well.
Mr. Miyagi said it best. "Best defense - No be there." Weaponry of any sort is no substitute for intelligence and situational awareness. If you make yourself out to be an easy target, you've already lost half the battle. This is not to say anyone should live in fear, but everyone who is planning on being on their own at night should develop some kind of street smarts. Learn to be absolute jerk to bums and anyone who comes up to you unsolicited at night or anytime really. When you're in a situation where you feel you might be at risk, such as walking to your vehicle alone (which is when a surprising amount of assaults occur) do not be talking on your phone, fishing for your keys, or anything that could distract you from keeping your head up and scanning 360 degrees. If something doesn't look right, it's probably not. In any case no security guard in the world is going to refuse a request to escort you to your vehicle unless he/she is supposed to be guarding a specific area. It's not being patronized, it's being smart.
And if you do decide to carry a defensive weapon, practice with it over and over again. You carry a gun, you go to the range and you practice firing it over and over again, and not just in a target stance. Do it off-handed, strong handed, in different positions if the range allows. You carry pepper spray, you test it in your backyard on something. This will familiarize you with the spray pattern and characteristics of the weapon, and have the added benefit of exposing you to some of the effects of OC. There's no real cheap way to get confident with a tazer, so if you're going to carry one, you need to go through a couple of barb packs just so you can get accurate with it.
I could go on and on but I won't. It's just that I run into too many of my female friends who think that simply carrying a weapon of some sort is going to somehow insulate them from any kind of a assault.