MgCl NaCl, CaCl, Na-Bicarbonate, and KCl can be all found in sea water and therefore in sea salt, which means that this salt appears similar to sea salt, but it is obviously not natural sea salt because the description of this HydraSense salt says:
The pre-measured and ready-to-mix salt packets contain: calcium chloride, magnesium chloride, potassium chloride, sodium bicarbonate and sodium chloride. Ingredients are not naturally sourced.
From this it's not clear if even NaCl itself is artificially produced or maybe they used sea or rock salt, purified it and added the mentioned ingredients.
Other sources (University of Missouri-Kansas City, Brown UniversityBrown University) say that un-iodized salt (canning, kosher, pickling, or sea salt) can be used for Neti-Pot. This means salt without iodine, anti-caking agents (such as calcium silicate) or anything else added, which can be then mixed with baking soda (Na bicorbonate). So, "table salt" which typically contains iodine, anti-caking agents and other stuff should not be used. On Family Practice Notebook they say iodine can affect the function of small hair (cilia) in the respiratory tract. For the actual saline solution to be as little irritant to the nose as possible, it should be isotonic, that is 0.9% (9 g NaCl in 1 liter of water).
I've found 4 reviews, all of which say that nasal irrigation with Neti-Pot may be useful for chronic sinusitis and some other conditions in the upper respiratory tract without any significant side effects:
- American Family Physician, 2009
- PeerJ, 2019
- International Journal of Environmental Research and Public Health, 2017
- Cochrane, 2016
I have found no convincing evidence to say that certain "special" salt, which can be expensive, is better than table salt.