Any recommendations for a singer with daily allergies all year and a dry/sore throat every morning?

I already see an allergist that gave me Astalin for my allergies. It helped a great deal, although not completely. I also use a Neti pot every evening. I drink plenty of water. I usually drink 2 liters at practice alone, and probably 3 liters on a normal daily basis. I even bought a humidified (warm mist). First night I had it it was all the way up and I woke up stuffy. On low setting though, my throat is not too bad when I wake up, although still a bit scratchy. I'm planning on buying a singers throat spray, but how often will I need to spray? I suck on menthol halls sometimes just to keep my throat lubricated and it helps my stuffiness. Is menthol OK for my voice? If not, what are some alternatives, and is there anything else I can possibly do to prevent waking with a dry throat?