Actually.... Know what a friend told me? Though he said it works for shrooms, I dunno if it works for weed.
He said that 1000mg of Vitamin C will make it go away. Soon enough, guess what I saw at a deli around the cash register area where they sell all the candy bars (delis always sell candy bars in front of the cash register). Packets of 1000mg vitamin C. You mix with water and kiss your high goodbye (hopefully).

@Orangeman, I feel ya. One time I ate rice with dry mouth and it tasted just like dirt (or at least had that earthy taste to it).