I'm with Dr Neil (and he is a Dr, but I wonder if he stayed at a Holiday Inn Express last night...but I digress). I use a neti-pot fairly regularly, I find it keeps the whole nasal plumbing clear and functioning without any potential side effects. In the end it's salt water, can't hurt from everything I've read...does it help, seems to help me, but opinions vary.
As for your original question, Dive Training did a recent story on OTC meds and diving (I'm thinking Jan/Feb timeframe). Two part, had a lot of information. Probably a good read in your case, DAN is obviously a good resource as well.