Dog dental product with xylitol?

There is a dental water additive for dogs that you add to there drinking
water that is supposed to help with tartar, bad breath and gum disease.
The product contains xylitol as well as CHX. I read somewhere that
xylitol is harmful to dogs. Would this be harmful to use on my dog? It
was prescribed by my veterinary dentist. It was developed by a Dr. Peter
Emily DDS who is supposed to be one of the leaders in animal dentistry
and is the author of several dental text books. He is also the chief
veterinary dental professor at CSU veterinary university. So it
apparently has some good research behind it. I am just worried about the
xylitol in it. It is called "Breathalyser" by imREX.