I had a nasty nasty cold before I flew last November. Everything was plugged and heavy. Otrivin worked a charm - I took two sprays (one to each nostril) 1/2 hour before flight. it took about 10 minutes to work and I was clear for 5 hours. It is in a black bottle with a gold label.
I also stock up on Zicam when in the US but I prefer Otrivin for the really nasty head colds.