-Drink Bleach - Essentially telling someone that you want them "fuck off" but in a more vile way of putting it.
-The phrase can also be used in a way that you would rather "Drink Bleach", than do something else that seems unpleasant.
Someone cusses you out. - A simple 2 word response might be "Drink Bleach". You are telling them that you want them to "fuck off" and die at the same time.