I read somewhere that the acid penetrates the exoskeleton and dries them out. Lemme see if I can find it and I’ll copy/paste.
Below is a copy paste: not my info.
Now to the interesting part. I became aware over the last few weeks, thanks to some customers, of an exciting application for Hypochlorous Acid (HOCl). It turns out that HOCl can be effective in Pest Control.
Here is where it gets strange (at least from my layman’s point of view). While HOCl has long been know to be effective in killing certain insects on contact, it is not effective on other insects.
To be specific, it has long been known that bleach kills bed bugs on contact. However, the use of bleach as an insecticide, is generally discouraged, because of health concerns, and the damage bleach can cause to property including corrosion and discoloration.
What is not as widely known, is that it is the oxidizing effect of bleach that kills the bedbugs by attacking and deforming the proteins in their exoskeleton, which happens instantly. The relatively small amounts of HOCl contained in bleach is what produces the oxidizing effect, so it only stands to reason that pure HOCl, would be even more effective, without the concerns of health or damage to property.
Where things get a little confusing, is that it does not have the same effect with all insects, even though all insects have an exoskeleton. For example, bleach does not kill roaches, unless they drink it or drown in it. It would seem their exoskeletons have a different protein makeup that is not effected by the oxidation.
One area where this has come up is with mites. There are many different mites that in aggregate afflict millions of people in the U.S. annually, and can be extremely difficult to control. Demodex, is a mite that lives under the eyelids and in the U.S. alone, is estimated to a afflict over 1 million people annually.
As there is a commercial treatment for Demodex, Avenova, whose primary active ingredient is stabilized HOCl. there has been some research done on its efficacy, with conflicting results.
While an article published by the NCBI concludes that HOCl does not kill adult Demodex Mites, and only kills them in the nymph stage. (The Dr. who wrote this report, disclosed that he was funded by a companies which make competing products, not to mention the fact, that if it does kills nymphs, theoretically, if applied regualrly, that would eventually should kill out the entire population)
Link to article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6689564/
The American Academy of Optometrists however, does recommend HOCl as treatment for Demodex mites https://www.aaopt.org/detail/knowledge-base-article/treatment-demodex-hypochlorous-acid-case-report.
While whether HOCl kills adult Demodex may be unclear, there seems to be consensus, that it does kill the Demodex nymphs. Additionally, often the irritation associated with Demodex, and other mites, is not from the Mites itself, but from the bacteria which they harbor, and HOCl is highly effective in killing bacteria.
Additionally, the same way HOCl is an effective manner of pest control for some insects, while having a very limited effect on others. It is quite possible that the same hold true for various types of mites.
Spider Mites have long been a problem in the agricultural industry, and it has long been accepted practice to use bleach or HOCl to control and kill Spider Mites.
So, while I have done some digging, it seems there is more digging that needs to be done. I hope to follow up with this post when I have more information to share.