I doubt you'd find a video dedicated to the whizzer, but there might be a chance. It's definitely a foundation of wrestling, and correspondingly, BJJ.
If you didn't already know, it's basically a powerful overhook that you can use to control your opponents. You use it a lot standing (ie -- a single leg defense,) but it's also useful when, for example, someone tries to roll up from half guard bottom, etc. In BJJ, I use it a lot to keep someone from taking my back, but you'd be surprised how effectively you can control or move someone with a good whizzer.