They instantly turn a dog that pulls on walks to one that walks by your side the entire time.

TOMFOOLERY I TELL YOU.

Ii don't know about instant but they are llike power steering for dogs if used correctly.   I had a very hyper Boxer that would act like a fool.  Our trainer showed us how to use the pinch collar.  Most of the unwanted behavior was gone after a few classes.   That stupid dog would choke himself out on a chain or flat collar if he got excited.

Yep. Prong pinch collars are power steering collars, no doubt.  And it's much more 'humane' than a choke chain, or similar. Once they get used to command and you break the stubbornness then you can go back to a martingale or regular collar/leash.

They do work well. Some show ring and training "purists" will scold you for using them, but it's hard to argue with the results.

What I like about them is that I don't have to use them.
I put them on my dogs, they behave, I never have to correct. I could tie a sewing thread to that collar and they would still heal.

My wife and I were 100% against those evil torture devices. We tried a ton of different collars (buckle, choke, martingale, gentle leader, etc).
We then went to a trainer that showed us how they work and how to use them.
My pitt mix pulled on a collar so hard, you could tie her to your car and she would tow it down the road. She hit the prongs once and got it. Now, she doesn't choke herself when she walks. I'm happy, she's happy and the collar just sits around her neck ready to be used if it's needed.

I now have them for all my dogs.

The one thing I have learned, however, is that I use a cheap carabiner to hook the prong collar to the normal buckle collar on the dog. I have had the prongs pop loose before (my current model has a punch clip, which works great, but can still release if caught on something). So, if the collar releases, the carabiner still holds onto the regular collar.

yeah with mine, all i have to do is give a little pull, not enough to tighten the collar, but to move the chains and she will correct herself.

It is just awesome.

chrismartin, we ourselves bought a "dominant dog collar" that goes on with the prong, so if the prong pulls apart it catches the dog. Great use of two collars to protect the dog.

You can do the same thing with a regular choker if you know what you're doing. When we got our rescue dog I thought a prong was the key. When I finally hired a good trainer the first thing he did was remove the prong and throw it in the trash. He showed me that if you know what you're doing you can accomplish the same thing with a prong and some knowledge. He was right.