Generally you are correct, but just remember that we never adviced against diving in sea water with eyes open. Don't think black tea should be a problem, considering that the water has been thoroughly heated before.
Yes, you can take my comment as nitpicking I suppose, since you do not have to drop anything in your eyes to be supposedly effective. I have no idea because I have not tried it myself but I do not see why I would not give this easy, cheap, and convenient method a try were I to have this issue.
We have a lot of "folk medicine" around this neck of the woods, too, and many of them do work great.
We have a lot of "folk medicine" around this neck of the woods, too, and many of them do work great.