Lets just say that was gross.
I kept imagining a huge, dead Gremlin, and I'm not sure why.
I have an idea, by the way :D
First, ya gotta shave his hair off. Make the man bald.
Then you pour hot tar/pitch in a cone his head. Or use a cloth to smear it around his face, whatever works.
You let it dry, and then rip it off. It takes out hair and lumps of skin.
You could set the pitch on fire before ripping it off, so he would endure the fires heat first.
AND, victims usually ran around bashing their heads/faces into things to try and end the pain, much to the torturers amusement.