How to Use a Neti Pot
Using an inappropriate irrigation liquid can cause discomfort and irritation. Isotonic saline (0.9%) is probably the least irritating and is most similar to the body's natural fluids. Pure water can actually be quite irritating. Solutions with a higher concentration of salt (known as hypertonic solutions) are sometimes recommended but are also more irritating.
There are several different ways to obtain an isotonic saline irrigation solution for your neti pot. Small packets are available that are mixed with a specified amount of water. Or, you could buy premixed isotonic saline, but this would certainly be very expensive for regular use. You can also make your own. There are various recipes that are recommended, and it is generally recommended that non-iodized salt be used for making a neti pot solution. It might be best to use the packets or premixed saline solutions at first, so that you can learn how it should feel.
If the solution is too hot or too cold, this can cause discomfort and may increase the "drowning" sensation. In general, it is recommended that the water should be similar to body temperature. You may find that warmer or cooler water is more pleasant for you.
Forgetting to keep your mouth open or panicking (or simply becoming too tense) may make the experience rather unpleasant and may increase the drowning sensation.
Final ThoughtsIf you simply cannot seem to get it right on your own (and insist on using the neti pot), you might consider getting help from a practitioner of Ayurvedic medicine. Keep in mind that some people may not be able to relax enough or are too uncomfortable with the entire procedure to ever find success.