I also take Oregano OIl --but not faithfully- When I do take it, I notice that my sinuses are very cleaned out.

I also have had experiences where I used to have sinus parasites -- (along with the symptoms of "itchy nose" and I could even feel their movement deep in my nasal sinus area. When I would light a Neem oil bug stick outside, I could feel the movement all the more.

Taking Oregano oil orally actually killed whatever was in there immediately . I also notice that if I were congested, oregano oil clears me out-- and rids any scratchy throat.

I read that Oregano oil is VERY anti-parasitic and anti-viral so I can see it having die-off symptoms. It is a good thing to have on hand during any epidemic. Sometimes it can be expensive-- but what also works for me is the Vitamin World brand that has buy one, get one free sales all the time-- so it ends up costing like, $9.99 a bottle that can last a year.