Review title is Messy & ineffective [SEP] Let me just start off by saying if you have a white sink don't even think about buying this product. It doesn't matter if you have running water going and you spit right in the sink, or if you spit it out with running water a foot away from the sink it's going to go everywhere... black dots everywhere.  I see Zero difference 2 weeks in from using this product. I would just spend an extra 10 or 20 bucks and get Crest White Strips.... if you don't believe me, buy it and you'll find out the hard way..