Oxymetazoline is super potent and works immediately on nasal passages, but it can be risky to stay on for more than a few days straight.

Steroids like fluticasone don't work immediately, and take a couple of days to kick in, but you can use them indefinitely. Also, in addition to opening nasal passages, they have general anti-allergic effects -- i.e. they can help with itchy, watery eyes and facial swelling.