Possibly the most practically useful college course I ever took was a 1-credit yoga class, to fill a Physical Education requirement. This is where I learned about "warm" and "cold" breath, and forcing breath through one nostril. If you experiment with breathing from the belly, breathing in through one nostril and out the other, you can actually coax the congestion to switch sides. I've personally found that switching congested sides can make it easier to sleep. The few breaths when the congestion seems to be balanced, is a good time to breathe some steam laced with wasabi or pepper sauce aromatics.