I have never used a Neti Pot, but I have read they can harbor bacteria. I always just poured the solution into my hand, and while over the sink sniffed it up my nose.
A better way is to get a water pic machine with multiple speeds. Fashion a tip that will fit your nostril. choose a mild speed at first and adjust the water stream to make it comfortable for your self. The solution should contain some salt small amount, or it will burn inside the nose. Warm the water add the salt and some Colloidal silver. This will kill any virus, or bacteria.
Never take antibiotics or you will end up with sinus problems as well as gut problems, Candida, IBS, etc.
I used to get 4, or 5 sinus infections a year. Did the antibiotics thing so I no what I speak of.
That was about the year 2000. Had all my amalgams removed and replaced with composite fillings. Had all the Root Canals removed completely. Haven't had a sinus infection since, nor a few other health problems. They all left within a few weeks, or so.
This may not be your problem, but food for thought.
Try this. Next time you have allergies, clean them out like above and with an eye dropper tilt your head and put a dropper full of CS in each nostril. See if the allergies go away.
If you don't make your own, you can get some here
http://www.tbyil.com/Utopia_Silver.htm
Would be nice to hear from you either way, if it works, or not.