Using a (fake) fetish to threaten Mictlantecuhtli.
Hellblazer: All His Engines (Chapter 5)
hellblazer: all his engines
Voudun magic.
Hellblazer: All His Engines (Chapter 5)
Summoning a demon.
Hellblazer: All His Engines (Chapter 3)
Spilling blood for Mictlantecuhtli.
Hellblazer: All His Engines (Chapter 3)
Fennel channeling Tricia Chandler and then a demon known as Beroul.
Hellblazer: All His Engines (Chapter 1)
John Constantine's Spells 