The term is so widely used that young men developed a game called 'Hunt the Grunt' whereby each player adds money to a pot and the aim is to score the ugliest girl/woman possible on any one night. At the end a winner is decided by popular (unpopular) vote and he takes the pot. It is then his decision whether or not to buy his grunter a drink with his winnings.
B: Get fucked, meat is meat and a man must eat.
"dropping a grunter" is the act of producing one of these intimidating steamers.
"he's in the bathroom dropping a grunter, i can hear him struggling with it from here. yeah pack me a cone too, he's still grunting away... we'll have enough time."
"rad... LOVE the grunter"
Sean: Holy Shit! that Grunter looks like he's the type of guy to eat a load of shit every morning!