I am 4 years out and still have to drink water with food sometimes, especially breads, etc. There may be some other solutions for saliva, but in my experience, they are extremely expensive for the benefit you get which is equal to using water in my case. Water, and therefore cheap wins. I have not noticed any flavor change though, so can't help you there.

It took 14 months for everything to taste the same as it did post-surgery and pre-radiation for me.