extract the urine
Definition from Wiktionary, the free dictionary
- (idiomatic, humorous) to mock, make fun of something
1997, Des Ryan, “Close brush with hairafter”, in The Messenger: Selected Columns from Messenger Newspapers, 1993-2003, 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.
This is a humorously "polite" way of saying take the piss.