I tried my friend's nasal wash on Monday. I'd been suffering terrible allergies on Monday, and the nasal wash didn't help me at all. My friend wanted to believe it had helped because I seemed to be breathing easier when I left her home, but within just a few minutes, I was suffering again.
If anything, I suspect the nasal wash made my symptoms worse by irritating my nasal passages and sinuses. They were never meant to have pressurized water irrigating its way through them, after all.