saline rinses work great. I had a significant reduction in sinus infections after a doctor told me about it. Never tried hydrogen peroxide.
I had an outbreak of hives a few years ago and have been taking 3 different medications(Claritin, Astelin and Zantac) every since to keep them suppressed. A very nice side effect of the medication is I haven't had allergy problems since then. The hive problem has been getting better, I used to take the medication twice a day, and a missed dose would result in an outbreak. I'm down to once a day with a smaller dosage and it takes a few missed days before the hives show up.