Many people use neti pots for sinus irrigation. Using them can reportedly help with infections, allergies, headaches, congestion, and other sinus-related issues.
Small packets of chemical mixtures are sold to be dissolved into distilled water for use within a neti pot.
The most commonly sold packets often include "pharmaceutical grade" salt and aluminum free baking soda.
Those packets quickly get expensive. They also are wasteful, as you have to dispose of the non-recyclable packets in the trash after each use.
A couple years ago, I researched making my own neti pot mixture. Not surprisingly, my research turned up information that conflicted with other information.
Everyone agreed that the solution should be primarily water. But some people insisted it must be distilled water, whereas others said they just use tap water.
Some people said just to add salt, others to just to use baking soda, others to use a mix. Some said if it burns to add more salt (and they explained why it seems counter-intuitive but how it actually makes sense when you look at the chemistry involved). Others said if it burns to add more baking soda. Ugh.
Another ingredient that was sometimes mentioned was hydrogen peroxide. Some people recommended adding about 1-10 drops of hydrogen peroxide to a gallon of salt/baking soda mixture. Some people said not to do that.
My notes are no longer available, so I've decided to ask here: What is an appropriate Neti Pot solution, and how does one adjust it for best results?