You don't need a netti pot - use a turkey baster and this recipe:

6 oz warm water

1/4 t. non-iodized salt

1/4 t. baking soda

Mix well.  Suction misture with a turkey baster, turn head sideways and squirt thru nasal cavity on the most open side and it flushes out the more clogged side.  Do not inhale.  Just let it flow thru the sinus cavity.  It worked GREAT, is cheap and I had instant relief from sinus congestion and sinus headache I had kept off and on for over a week.

My doctor said do NOT use water without salt.

I found this recipe online and was hurting, didn't have a netty / netti pot and thought "Why wouldn't a turkey baster work?" 

It did!