Extract The Urine Meaning

(idiomatic, humorous) to mock, make fun of something

Example: 1997, Des Ryan, “Close brush with hairafter”, in The Messenger: Selected Columns from Messenger Newspapers, 1993-2003[1], Wakefield Press, ISBN 9781862546134, published 2003, page 42:
  Now, Merilyn is neither bizarre nor eccentric in the ordinary sense but when she started talking about the ‘presence’ in her shop I thought she was extracting the urine.
2001 August 19, "BigAl", “Re: fare thee well”[2], alt.music.leonard-cohen, Usenet:
  Actually Connie it refers to the way we extract the urine out of the apparent social differences between each country.
2006, Tyne O'Connell, Dumping Princess[3], Bloomsbury USA, ISBN 9781599901503, published 2007, page 34:
  This is what the English do; take the piss (or as we say at school, extract the urine).