Is that sterile?
It is if you boil it...............
I use boiled tap water from a sealed container and a self made mixture of 50/50 table salt and baking soda.
I pre-mix the salt and soda in a sealed container, 1/4 CUP of each, shake well.
Then when I use it, I use 1/4 TEASPOON of the mixture to one bottle of boiled tap water. One bottle per nostril.
The bottle is a soft rubbery squeeze bottle so that I can apply more force than those Neti pots. It works great!.........
Distilled water ONLY.