In a similar vein to jalapeno peppers and cayenne, I have found that a good, hot curry (as in suicidally spicy
) works wonders.
In addition to helping to clear the sinuses, it makes you sweat which aids in removing some of the toxins from your system.
Another thing that works well is a steam bath..
Boil up a large pot of water with something like Vic's Vapour rub added into it. Grab yourself a big towel, place your head over the pot, and the towel on top of your head. Stay beneath the tent for as long as you can tolerate; you may, periodically, have to come up for air.