Saline washes are good for cleaning out the nose and sinuses. If saline is not available, you can make it yourself by filling an 8 oz. glass with luke-warm water and stirring in ½ to 1 teaspoon of salt (canning salt seems to work best) then adding a pinch of baking soda. Fill a bulb syringe with the solution, and while standing over a sink squirt and sniff the solution up one nostril until just before the solution starts running down the back of the throat. Wait a couple of seconds and blow your nose back into the sink or a tissue. Repeat on the other nostril.
What this does is washes out the nose and sinuses. This can either be done in the evening after your nose and sinuses have collected the irritants during the day, or in the morning if nasal CPAP/BiLevel has dried out your nose or sinuses. Your can also get a saline wash kit at your grocery store or pharmacist.