Portable perfume
The air inside a plane can become stagnant pretty quickly. Considering it is the only thing you will smell throughout your flight, consider an alternative. You can bring portable fragrance bottles to help you cope with long, smelly trips.
They aren’t that expensive, and you can fill them with your favorite perfume or cologne. A little spray can go a long way. When something smells a little funky, spray the bottle and immediately notice the difference. For a quick refresh, you can also spray yourself when you get off the plane.