Goofer Dust

Goofer Dust is a powder- and confetti-like substance used in hoodoo rituals. It's only known use in the Supernatural universe is as a ward against Hellhounds, similar to the way a line of salt works against demons.

A drawback of Goofer Dust is its nature as a powder. If not protected or maintained, a line of it can be broken or eroded by moving air -- even that exhaled by the hounds themselves. Demons (for whom Hellhounds work) can also break the line, if the case may be. This makes rock salt a better alternative, given its weight and antagonistic properties against demons.