Drawn and quartered.
Given a C4 enema.
Strapped to the underside of a car/wagon going over a rocky path.
Given cement shoes and throw in a river.
Put through a wood chipper (very messy).
Run over slowly by a steamroller.
Get their necklace caught in an escalator, results in slow stragling or slow decapitation.
Forced to eat a bowl of broken glass.
Roasted alive in a giant oven.