How does hot/spicy food clear sinuses?

I have all kinds of sinus and allergy problems. My nasal passages are very narrow and they get clogged, when I go to yoga I have to put on a breathe-right strip just to get through a class.

Anyway, I made sushi last night, and I guess on one piece I put a little more wasabi than I had intended and didn't realize it.

Well, after a bit of a shocking and uncomfortable moment, with some kind of heat explosion that went through my whole head, I had to blow my nose.

My sinuses have been clearer than they have in months ever since.

I am just wondering if anyone knows what causes that, and if it's dangerous in any way (health-wise).

Because, dang, it works better than any meds or sprays I've ever used, I'd be willing to dab some wasabi on food every couple of days or so if it will keep my nasal passage this clear.