Sling your hook

‘Sling your hook’ is polite way of telling someone to go away. 

This term has a nautical origin.  ‘Hook’ was a name given to the ship’s anchor, and the ’sling’ was the cradle that housed the anchor.  Therefore, to ‘sling your hook’ meant to lift anchor, stow it and sail away.

from http://www.grammar-monster.com/sayings_proverbs/sling_your_hook.htm