If the antibiotics aren't working, its because the infected mucus becomes encapsulated and the drugs won't penetrate.. bigkev has the right idea, but gravity will prevent the saline from reaching your upper sinuses, where chronic lives.
The following technique will remove the infected mucus from all sinuses, using gravity instead of fighting it, and the journal explains the Mayo Clinic research which confirms the technique.
http://www.medhelp.org/user_journals/show/2322
The Flip-Turn Sinus Flush is mildly risky, because you have to bend over to do it, preferably in a shower, but you can also do it outside on soft ground, or you can kneel down and lean over a bathtub with the shower running.
Good luck