Chewing on fennel seeds is very helpful for dry mouth. They are tasty too.
Dry mouth is much better now with chipmunk style org. fennel seeds. I just tuck 5-10 seeds above teeth and now, ta-da, I salivate at night. I feel increasing my mineral intake helps too. Also, drinking plenty of water...and when I don't remember, I drink 3 glasses at bedtime.
I'm also making my own tooth paste from coconut oil, baking soda, EO, xylitol and just looked up DIY mouthwash after reading your post.
I have lots of essential oils (EO) including Cinnamon, Peppermint, Spearmint, Myrrh and Clove which I'll use (2 drops of ea). Based on the recipes I found, I'll add a good mineral salt, xylitol, citric acid and distilled water. Maybe some colloidal silver, too.
You could buy a few oils (they'll last a long time) or a bottle of thieves or good Samaritan oils and DIY. But beware! DIY is addicting. Fun. Cheap. Just be careful to use clean jars and the natural preservatives.
Dry Mouth & Dry Eyes Help
My problems with dry mouth started when I began taking an anti depressant. It only affected me when I would lie down to sleep. The dryness was so bad that it was seriously interfering with my sleep. I do not like the idea of taking things with sugar, sugar substitutes or any kinds of chemicals and putting them into my mouth to stop the dryness, tho when I did give in and try some OTC products, they didn't help much.
What has helped dramatically with dry mouth has been fennel seed, organic. Right before bed I take about 1/2 tsp. and chew it a little to soften it, then use my tongue to tuck the seeds under my upper & lower lip, between there & the teeth. The flavonoids in the fennel causes me to salivate, but not to a bothersome extent. Sometimes the little seeds fall down onto my tongue at night, but that doesn't hurt anything & I never have come close to choking. Works every time! For dry eyes, I noticed one commercial product had castor oil in it, & some kind of chemical. Every night before I got to bed I wet my finger with castor oil, not so that it is dripping wet. Then I rub the inner side of the lower lids with the oil, close my eyes & roll my eyes around. It helps a ton!