Vaseline or any oil like coconut or olive oil. Vaseline is less messy
Eucalyptus essential oil
Run a bit of Vaseline on the chest followed by a drop of oil, rub it all together. Ensure you don’t put too much oil as it can burn if overdone. Don’t put it anywhere else on the body, avoid eyes and mouth.
Alternatively for during the day put a drop or two on a tissue or a cloth and smell when needed to open up those nasal airways.
Very simple and effective