I don't think there is anything wrong with issuing some discipline to your students, or correcting any rude Chinese for bad manners or impoliteness.

I remember one Chinese at Beijing told me:"My country, my airport, I can have any opinion about foreigners I like!". I played all nice until we got inside Heathrow after the long flight and then said to her:"My country, my airport, ask a Chinese student for help to find the gate for Newcastle yourself b***h!"