I saw the videos on Youtube and thought it was a hoax for sure. But then I bought some of the Crest whitening toothpaste, and used is on each headlight and after rinsing off the lights, I was amazed they were clear. I understand this is only temporary and will need to be done again, but I am still shocked it worked.
You can also put a coat of Auto Polish on there... make it last longer.
I've tried several of the kits, as well as the blue stuff with 2000g sandpaper, and it lasted for about a year each time...Now the headlights are back to being foggy, and it may be worse than it was before.