Many SE Asians use toothpicks after every single meal. There are always toothpicks on the tables, and someone is always picking away somewhere nearby. However, it’s apparently offensive to show your teeth when you using your toothpick because people hide their mouths with one hand while they pick their teeth with the other. However, nobody seems to mind when someone is picking their nose. Walking through the streets and markets in Vietnam I saw people digging for nose potatoes all the time. In Hanoi the waitress standing across from my table was picking away deeply into her nose and rolling away the bugers to the floor while I ate. While behind her, someone was carefully picking their teeth with one hand over their mouth. So picking your nose in public is ok, but showing your teeth when you use a toothpick is offensive. Get it? Neither do I.