The initial idioms of the letter C

clean slate	clean someone out
clean someone's clock	clean sweep
clean the floor up with	clean up
clean up act	clean up on something
clean-cut	cleaned out
cleaner	Cleanliness is next to Godliness
cleanse the Augean stables	clear as a bell
clear as crystal	clear as mud
clear as vodka	clear away
clear for publication	clear from some place
clear (one's) lines	clear name
clear of	clear off
clear one's name	clear out
clear out of some place	clear sailing
clear the air	clear the deck