Stains easy, only use half a tablet, no instructions at all.
These are true to what they are supposed to do, however it took me about 10 minutes to get the purple out of my sink and my 9 year old son almost 35 minutes to get *most* of the purple out of his mouth even after mouth wash good brushing and flossing. Sadly he asked to stay haome from school tomorrow if his mouth is still purple. Definitely only use half a tablet if you are going to use these and run water in the sink while spitting and rinsing.
Rating: 2 stars