There's certainly a number of Russian words in older Warsaw slang (barachło, ustrojstwo, wierchuszka, etc.), but the videos were not using slang, especially not

There's certainly a number of Russian words in older Warsaw slang (barachło, ustrojstwo, wierchuszka, etc.), but the videos were not using slang, especially not older slang, and they had no reason to use prawilny except by accident.