Non-Staining Blood
Non-staining blood? Well, it depends on what the blood is made out of and what you put it on. But whatever kind of blood you choose to use, I highly suggest not using it on your bare walls or floor because there is a good chance it won't come off. However, all is not lost. You can lay clear plastic sheets over the walls and the floor (use tape to make sure sheets stay in place) and splatter/smear blood on that (use a certain type of blood, perhaps gel based blood, so it sticks onto the sheets). Once you have no further use for it, simply throw the sheets in the trash, no mess, no fuss.
Although it won't look as good as you might have invisioned, think of it this way: Some psychopaths cover rooms in plastic sheets to make sure their victims' blood doesn't stain and leave evidence in their homes.
