For sinus congestion, I highly reccomend the sinus flush kits I saw in the drug store the other day. It comes with the pot you use and the solution. Sinus flushing is immediate relief, can be done as often as need and has NO side effects. If his sinus are inflamed, the first 2 to 3 times he does it they will burn like salt in a open wound but then they start to feel so good you LOVE it.

After he uses up the solution if he needs to keep flushing (which I doubt he will) you can use bottled water with a pinch salt and that is super cheap!