Mix 1 cup (8oz) of warm water with 1/4 tsp of non-iodized salt (such as pickling or canning salt) and 1/4 tsp of baking soda. Stir until dissolved.
A simple yet effective technique is to pour salt water solution into one nostril and let it run out through the other while the mouth is kept open to breathe, using gravity as an aid. The flow of salt water through the nasal passage flushes the dirt, airborne allergens (dust and pollen), pollutants and bacteria-filled mucus.
There are many different neti pots available for this purpose. You can also use a bulb syringe. Remember to wash your hands and all pots or syringes. Then air dry them.
It's important to keep it all clean you don't want to introduce germs but wash them out while you are rehydrating your nasal passages.