Andrew111, the general rule with xylitol is "Thrive for Five". Five contacts a day to keep things in balance. Xylitol will also protect the teeth as it is carie-static, but not from remineralization. Xylitol destroys the bacteria that causes tooth decay.
Try some of the lemon Dr John's candy, as lemon also is can stimulate saliva flow for some. I have tried many xylitol candy and found Dr John's works the best for me and after several months, my saliva returned significantly. However, I also used PerioSciences ProVantage hydrating oral gel along with the candy. I can walk outside in extreme heat for an hour without a water bottle for the first time in a decade or so.
Keep the xylitol away from dogs, too. Although studies have shown it takes quite a bit to have an effect, I wouldn't want to test it on my little dog.