Do you smoke cigarettes? If so, switch to cigars and blow huge plumes in people's faces and then spit at or on them when they start to approach you.
If you don't smoke and are unwilling to start, try getting fake Halloween teeth that look rotten, and carry a bag full of smelly garbage with you everywhere. If approached give a huge teeth smile and start unloading your garbage all over the ground and shouting about how they are trying to steal your grandma's heirlooms.
