I ordered both the spray and brush away gel and have been using the spray on Harley's plaque stain spots for almost 2 weeks and the improvement is amazing! I use it once a day on him and spray once on each stain on both sides of his mouth. I'm only using the spray right now to see just how well it works and will try the gel later on. (it says that the brushing gel works faster than the spray). I just wanted to share my experience in case anyone was considering trying it. The ingredients are all natural and totally safe which is exactly why I purchased it in the first place.
Here's the link!
http://www.petzlife.com/