Oh shit, Sean that filthy mother fucker, makes an amazing come back. After being racked once by Cheng, Sean gives Cheng the dirty chink special and racks Cheng two games in a row.
-New York Times Sports Section Nov 11th,2007
A group of girls that one would generally agree are filthy or dirty in a sexual sense. May not be a negative even though the word implies a negative connotation. Could be a sarcastic way to say that a girl is hot and (you hope) dirty.