I love the stuff and have been using it for over a year. Maddie's teeth are as clean as a whistle...but they were clean when I started using the stuff. My daughter had Maddie's brother and doesn't use the pezlife on him and you can really see a big difference between his and Maddie's teeth! I mostly use the spray...it's just quicker and easier. For those of you who want to see before and after pics, go here:
http://www.petzlife.com/