Coochie punch is the action where you fist a woman with your hand lubed in vaseline
{chad} hey dude i just coochie punched {kira}
{jake} yooo did u use the vaseline lube
Dusty Cooch is a vagina which serves as an ashtray for many people, most likely discordmods.
It can also mean that the cooch has been infected with many sorts of STIs resulting in a dusty cooter.
{chad} yooo dude we used {kira's} Dusty Cooch
{kyle} wooah bro that must have reeked of STIs