Wiktionary
goofer dust
n. (context US English) A powder used to cast a spell.
Wikipedia
Goofer dust
Goofer dust is a traditional hexing material and practice of the African American tradition of hoodoo from the South Eastern Region of the United States of America.
Usage examples of "goofer dust".
At the moment she would have given one of her unpaid week's wages for some Long John the Conqueror Root, or, better still, a pinch of goofer dust.
If a person ever needed a sprinkling of goofer dust, and needed it bad Miss Baker was undoubtedly it.
They say she can threaten kids sort of scary with chicken claws, African goofer dust, and such.