Neils Sinus rinse has become my daily routine to combat sinus infections. I pour distilled water into the plastic bottle warm it in my microwave for 30 seconds then empty the Neils packets into the bottle, shaking it then using it in each nostril. Neils Sinus Rinse comes with directions. It says to disinfect the bottle place it in the microwace for one minute. So far so good. Longer will melt the bottle I learned.
My allergist also has me using Fluticasone nasal spray daily to keep my sinuses from swelling and plugging.

The straight Neil Med bottle can’t be boiled 10 minutes. I called and they said 5” max. They have started making a Squeezie nasal rinse bottle that can be boiled and I switched to it. I do prefer the original because it’s simpler confirm the volume to add the med to (the design makes it have air bubbles), but being able to clean is more important. If you’re just adding saline, that won’t be issue and some prefer the Squeezie. .
I found the squeezie at CVS once, but usually get from Amazon.

Be sure to say KAAA as you initiate rinse to keep fluid from ears.