i rarely get styes, but every 10 or so years, i am afflicted. How annoying it was to find out the OTC mercuric oxide cream that i had used for since childhood to treat styes is now no longer available, -- having been deemed "unsafe' because of its mercury content!
the small tubes has a use date that used to be good for 3 to 5 years, but were always expired by the time i got my next sty. each tube contained less than an ounce of cream, and less then 10% of a tube was more than enough to treat a sty.
i get more mercury from my infrequent intake of tuna!