This is what the URL looks like in your PM: https://bitcointalk.oгg/index.php?topic=5338607.60. But if I post it, theymos converts it into normal characters again so you don't see anything special. Click loyce.club/other/non-ascii.txt to see what it looks like after saving in a text file.

The word "bitcointalk" is normal, the "org" has a non-ascii character.

In Google's search field it looks normal:

In DuckDuckGo's search field the "r" looks off:

If you search the fake "oгg" on Google, you'll notice the difference.

It's a smart trick, and I don't think it can be prevented without making PMs in certain languages impossible.