In the course of polishing up our colloquial French we came across this:
Le groupe du matin est très bien, mais alors l’après-midi, c’est comme pisser dans un violon (the morning group was fine, but in the afternoon it was…)
The phrase has various meanings:
– trying to get blood from a stone
– handing out my own farts
– talking to an empty cupboard
– banging my head against the wall
– discussing Brexit.