Wait what, you actually put a sign on your door? That's like college dorm stuff with the sock on the doorknob. It's wild to me that a piece of paper is still the best fix for getting your family to leave you alone. Most people I know just put on big headphones as a universal back off signal. A physical sign seems so formal for your own house.

Ice water never worked for me, just made a mess.

Another country? How did you even notice that alert?