Embalming someone. While they're still alive. Fairly quick, or slow, your choice really. Also very, very uncomfortable having a the fluids enter your bloodstream. Not pretty.
Even worse, and one my personal favorites, from all the way up to the land of the rising sun comes the "Eels". What happens is your stripped naked and a series of eels are inserted into your anus. The eels will slowly wiggle around inside of you as they slowly but surely devour your rectum. If you somehow don't die of shock or internal bleeding, you most likely will after the eels begin snacking on your intestines. Not too pretty, and if you're really unlucky, they might stick you in a vat of incredibly cold water for a good bit first, or stick you in a tub of electric eels. Or any combination of 3.