I can only tell you of personal experience. Nothing works if YOU don't believe it.
I don't agree with this. If someone gets caught in a proper rear naked choke, whether they believe in it or not, they will go out. I train this technique, and I don't have to worry about how they hold their tongue, lift their toes or if they believe that they can be choked out.
I personally would not teach a technique, as a self defense technique, if it requires the attacker to believe that they will be taken out by it. I would be afraid that the student might believe me, and try it, in a real situation.
My experience in pressure points, is similar to what other here have said. Each art contains them, as part of the techniques they already study. For example, we have an art where a punch is thrown, the other guy parries, enters, breaks uke's balance and structure, applies a pressure point, then executes a take down. I find that in practicing the kata, I can now hit that pressure point very accurately, and get a massive effect... when practicing the kata. Even when we run at full speed, full power, or put it into another combination. However, once we go into randori, the effectiveness goes down dramatically. Is it because the other guy is no longer a willing participant? I don't know.
Another experience I had, was with a restorative art. When we choke someone out, there is a nerve in the neck that you can excite to wake them up. When practicing, exciting that nerve, if done right, will cause the guy to flinch pretty good, and you can get both feet off the ground. (he is laying down... ) When I had my black belt exam, and got to that technique, I had the added pressure of highly ranked people judging my every move. I got a little excited, hit the nerve pretty good, and the poor guy flinched so hard, it looked like he levitated about 4 inches straight up off the mat.
So, my take on these techniques is that they are valuable, when worked from the outside in. In the take down version, I am first defending, entering, breaking balance... before applying the pressure point... then immediately following up with a take down. If I get the "randori" effect, I mentioned... which is not much... its ok, he is still going down. If I get the other "levitating" effect... AWESOME... he is still going down. What I think is most valuable, is practicing that pressure point in the middle of the combination. It is a small target, that must be hit with the right surface, in the right direction... this accuracy requires me to focus on getting all of that right. In the mean time, I am letting my subconscious mind or muscle memory handle the punch defense, entering, off balancing, and take down... while I am focusing on something else. Pretty soon, the rest of the combination and the other moves get better... and I get to practice them without thinking about them. So regardless of how well the point actually works on this particular guy, the rest of the technique should.
I find that when practicing the pressure point first, you get the least amount of time working on the other parts... and it is the other parts that have the higher effectiveness. (they don't rely on any belief from the other guy)
Working from outside into a pressure point, I find it worth the effort. It gets you to practice your basic arts, with out thinking about them too much. It gets you to practice things in combination. Your actual mileage from the pressure point will vary, depending on a lot of things. But that's ok, as you are not relying on the pressure point to finish it. If it does, you have a really good story. If it doesn't, all the higher percentage stuff you did before and after, should do the trick.
