My mother has found that certain of her other medicines, especially her high blood pressure medicines, add to her dry mouth. Her head and neck doctor and her general practitioner are discussing changing her medications, but meantime she has found relief at night with several of the over the counter products for dry mouth that the pharmacist has "behind the counter." All seem to be glycerin based washes or swabs. They aren't terribly expensive, but then you don't get much. I think Brian's idea of a homemade concoction is worth a try.