After using nasal sinus rinse for approx. 2 years, I'm suddenly experiencing what I would call a mini sinus infection which lasts only a day, producing thick yellow mucus, but then going away after only a day. That happened to me on Saturday and now today (Monday) it seems to be happening again.
I'm using a brand new top since the one I was using fell into the toilet, and I always rinse both that and the bottle off with hot water. I was told it wasn't necessary to boil the water that I use, that tap water was safe to use. Can the rise action itself be causing this new symptom?