Salt

In the world of Supernatural, salt is used as more of a weapon than to help with taste buds. Hunters like Sam and Dean often use rock salt to repel ghosts, demons, hellhounds, and other supernatural beings.

More Information
When Sam and Dean were young, John made them always salt the doors and window when he left for a hunting job. This was for their protection, and helped John know they would be safe.

Salt can be loaded into a shotgun cartridge and fired at a spirit, forcing it to dissipate harmlessly for a short time. This does not destroy the spirit. Salt can also stop spirits and demons from entering a room if a hunter simply spills a line of it in front of all entry points, like windows or doors. It can also be poured, or spilled, into a circle around a victim to repel a spirit from attacking them. A spirit can also be encircled by salt to prevent it from escaping, much like a devil's trap. But if the line of salt is broken by any means, the spirit can get through.

Salt can even be used to purify a human corpse or to torture a demon by pouring salt down the host's throat. It can also be used to force a spirit out after possessing a human.

First Appearance
Used in a Gun- Hook Man

Used to Burn a Corpse- Hook Man

Used to Ward off Demons- Devil's Trap

Used to Trap a Spirit- No Exit

Used for Protection- Pilot

Used to Force a Spirit Out- After School Special