It could be a matter of learning how to speak without spraying -- saliva is, after all, an important part of both of our immune system and digestive system. Obviously I don't know what's going on, but just wondering if you're sure you have "excess" saliva or if it's a habit of speaking that some people develop.
Dentists at Wake Forest Baptist Health say that apples, green beans, cauliflower, carrots, celery and other firm fruits and vegetables promote the flow of saliva.
http://www.healthline.com/health/drooling