It's probably not best idea to scare everyone that goes in your bathroom or you might find your house plants mysteriously withering. It might be yet another shower curtain (see below), but the Scary Shower Curtain has the eerie shock factor without the blood.

It might not encourage guests to shower but in this day an age we can all do our bit to save water.

Also see the Blood Bath Shower Curtain or the Psycho Shower Curtain.