My wife learned how to use those muscles in college while having a lot sex with men other than me. Apparently, she and her roommate found an article on it and exercised to get the skills. She was the most popular fuck toy at her university until we decided she should stop dating others. Since then, only a handful of men and I have had the privilege of enjoying her magic pussy.
Some are indeed better than others, but I don't know about THAT much better. I will say - I had one girl that had a "Magical Mouth" - fuuuuck I don't know how she did it, but she gave the best blow jobs in the world. And she was sooo into it. Man I miss that