do (one's)/the dirty work(redirected from do their dirty work)
do (one's)/the dirty work
To do the unpleasant or challenging tasks that someone else does not want to do. The boss will just get one of his thugs to do his dirty work, as always.
do someone's dirty work
COMMON If you do someone's dirty work, you do something unpleasant or difficult for them because they do not want to do it themselves. He's always got other people to do his dirty work for him. She can do it herself — I'm not going to do her dirty work for her!