My throat does occasionally become very dry. Seems as if that happens when I eat something acidic, like red sauces. I've developed a sensitivity to some foods with red sauces, orange, some chocolate, and peppermint to name a few. What's strange, I can tolerate pizza one time but if I eat leftovers the next day, it'll make my mouth drier or my throat very dry. Thinking it's a spice in the sauce. When my throat becomes very, very dry, the only relief for me is drinking milk with vanilla ice cream. I know sugar is not the best solution but it gives me instant relief. When my mouth gets very dry, sprays or water does not help.
Hope this helps. I know how it is!!