Gold Dust was a line of all purpose cleaning agents that were first marketed in the late 19th century. These agents were produced by the Nathaniel Kellogg Fairbank Soap Company. The mascots for this product were the Gold Dust twins "Goldie" and "Dusty", which were two young black children.
An advertising sign for this product was available for sale at Feinberg's Loan and Pawn in San Francisco in 1986. (Star Trek IV: The Voyage Home)