Amber, I am actually working on researching to do some hubs based on natural remedies using foods and herbs. After seeing your question I looked into this and found "Horseradish root" can be used to help congestion and sinus issues. You can either slice it and smell it or slice it and chew on it to help relief congestion. If you try chewing it, start with a small piece and increase the size if needed.
Pelargonium root, Echinacea, and Eucalytus is said to help Sinusitis as well. A local health food store may carry these.
I should have my first article about natural remedies up soon if you would like to follow me.