Why does smirnoff taste different in different countries?

So basically whenever i drink smirnoff vodka from countries like Estonia or Greece (any balkan country really) it feels more pure and clear, it has a very sliiiight turqoise color if you look at it really closely and it is really easy to down larger amounts of it. But whenever I drink smirnoff vodka from Sweden it just feels thick, it looks really clear almost too clear and it makes me want to vomit, even just by sipping a little bit i can feel like what i can best describe as a lowk gag reflex. I have read about the conspiracies that in sweden they put something in their liquor that makes you throw up if consumed in larger amounts but is that really true? atp if not idk what it is but something is literally different about it, does anyone know?