The allergist I just saw said do nasal washes because the excessive saliva is from Post-Nasal-Drip. She also said PND can cause GERD. I looked at how to do nasal washes them on line and I freaked. They say a child can do it, but I'm not sure it is that easy. Also, GERD can also go up into the sinues and cause the PND, which can then give you a bad taste in your mouth. Hope you find relief soon, because I haven't.
it's probably from the drainage of your sinusis.