When you pour vinegar in the butthole of a dead human or other mammal and you insert your erect penis in said butthole and leave it in all winter so that when you take it out in the spring your dick is pickled and will therefore taste better.
"Will, my girlfriend was complaining about the taste of my dick so I did the hibernating pickle and she's never been hornier!"
"Jesus, Owen, that's fucking disgusting!"
"Hey, don't knock it till you try it."