Dirtballs

S41 E24: If there's one thing Oscar the Grouch hates, it's cleanliness. He starts a new company, Dirtballs, to spread dirt all over Sesame Street. But as Oscar gets to work, the extra dirt seems to make his neighbors happy. Yuck! Also: Usher teaches Elmo about the word 'volunteer.' Brought to you by the letter D and the number 17.