Found this interesting information a few days ago:
Clear your stuffed nose!
Forget Sudafed. An easier, quicker, and cheaper way to relieve sinus pressure is by alternately thrusting your tongue against the roof of your mouth, then pressing between your eyebrows with one finger. This causes the vomer bone, which runs through the nasal passages to the mouth, to rock back and forth, says Lisa DeStefano, D.O., an assistant professor at the Michigan State University college of osteopathic medicine. The motion loosens congestion; after 20 seconds, you’ll feel your sinuses start to drain.
So, I hope this helps. Though I suggest performing the suggestions in the safety (or privacy) of your own home.