My DH's ENT doctor had him use that for sinus troubles. It wasn't magic but it did help. You can mix it up yourself if you want and squeeze it in with a snotsucker.

Also, this isn't exactly sinuses but may help-- when I had a BAD cold in February and (correctly) suspected I might be pregnant and couldn't take my usual Sudafed, I sucked on menthol cough drops. They helped. And I rubbed mentholated lip balm right under my nose. Like Vapo-Rub I guess.