I really feel your frustration that comes through your post. I don't have a great answer to give - just that I finished radiation right around the same time you did and still have a very dry mouth. I have just learned to deal with it. My saliva isn't as sticky as it was during and immediately after radiation - but it is still thick, still sticky. I do have some wet saliva, but definitely no where near adequate or what it used to be pre-treatment.

Here's what I do to cope: I threw away all of the Biotene products after getting so frustrated that nothing seemed to help. I actually felt better once I said "to heck with this stuff" and moved past trying to get relief from them. I never try to eat anything without water or a warm beverage (I've found that drinking warm coffee/tea while I'm eating warm food works better than drinking cold water with it). The times I have tried have been miserable and unsuccessful to put it mildly! I use a ton of Burt's Bees lip balm because my lips are always dry and I don't have saliva (or much of a tongue!) to wet my lips with. I always have a bottle of water with me when I'm planning to talk a lot (I teach health and safety courses, so I'm frequently talking a lot!) and I take frequent small sips.

As for bed - the time of day I dread - I used to keep water by my bedside, but have since given that up. Like the Biotene - once I finally said "this just doesn't work for me" and stopped trying to take a sip of water that would moisten my mouth for 6.4 seconds before it became a barren wasteland again - I learned how to just deal. I have learned that - and I know this sounds weird - but there you have it! - that if I stick my finger in my mouth in the middle of the night and run it across my teeth, I produce some small amount of saliva and my mouth feels a bit better. I barely wake up and can go right back to sleep. In contrast, when I was sipping water all night long I had to wake all the way up to unscrew the bottle cap, sit up in bed, take a sip of water, work on swallowing it, putting the bottle cap back on, and then tried desperately to get back to sleep. That was really disturbing my sleep patterns!

When I get up in the morning, the first thing I do is take care of my oral hygiene, then I go get a huge cup of warm tea. It does take a while before I am lubricated enough to be able to talk, but my family now knows not to bug me until I can talk. I let the phone ring if I'm not ready to talk and I never schedule very early morning classes. That's just the way it is.

I don't know if my quirks will help you or not - but I really wanted to answer.