Simply squeezing the 1 lb bottle pointed directly up the chimney flue near the top of the firebox, the powder is carried up the chimney coating the entire surface of the flue and enabling the ingredients to start working! It also modifies third degree creosote by converting it into a more brittle state. During the heating and cooling cycles the treated creosote loses its adhesive properties so it can be simply brushed away, with no problems at all!