Does it work very well? I am thinking about trying it since Nite White 22% failed to give me the results I was looking for. I went to Kor website to find a dentist near me who uses Kor, but neither are using it anymore. Does it still exist? One of the dentists is using another Deep Bleach called Pageant White. I wonder if that's as good. Does it matter what bleach you use or is it all in the way the trays fit? I'm confused!