I read somewhere, wikipedia i think, that Delsym cough syrup can help because it affects the nervous system in some way.
I went ahead and tried it this weekend. Either it's helping or I'm going through a good spell. I came home with burning all over my cheek today, took a tsp, and started to feel better.
Just throwing this out there. It's expensive here -- $16 for an 8oz bottle -- but you can't put a price on feeling even a little better.