If there are Mexicans or Latinos, wear an ICE jacket, that would scare the crap out off me, if there are blacks, quote KW, "bush doesnt care for black people", Asians, make the place look like a DMV and dress as a driver instructor, White kids, tell em Jesus was black, or even better, dress after what they will fear the most after eating lots of candies, a DENTIST!!!!
All is just harmless jokes and fun, if they don't get it, tell em Spongebob is not real.