Nobody is a bit weary of posting this, it not only edges close to source discussion (the mods have been talked to and said it was OK), but it opens up a new market for a mind altering substance. We've all seen what happens when dumb kids learn they can buy legal drugs, so nobody hopes you will be smart and discreet with what is contained here.
In Islamic cultures, Syrian rue seeds are burnt to protect against the evil eye. They go by many names, harmal, esphand, aspand, yüzerlik or üzerlik. depending on the country. What is of interest is the fact they are sold in Islamic or Halal* markets for this purpose. Now it is rather unlikely that the people selling these seeds are fully aware of their capabilities, so some level of polite discretion is necessary. Ask using the names listed, mention "throw it into a ban for incense to dispel the evil eye." and don't go telling everyone you meet about a "new source for drugs". Remember, Islam has some pretty strong prohibitions against intoxication and they may consider it highly inappropriate for people to be using the seeds in a non-proscribed manner. Don't even hint at it, don't ask if it's safe to eat, don't ask "is it potent", not worth the risk.
Nobody will be assembling information on ritual use related to the evil eye soon enough.
While you're shopping, most Islamic markets also carry hookahs, shisha, and a wide range of tasty sweets.
Love.
Potter.
*This is the Muslim equivalent of a kosher deli, all products are certified to be 'clean' in accordance with the Koran. This is not a proper noun and does not name a specific market.