An implement for treating strands of hair comprising a reservoir containing a composition and guide means capable of sliding in the reservoir. The guide means comprises a body extending through the reservoir, pulling means (e.g. a pull strip) protruding from one end of the reservoir for at least partially pulling the guide means out of the reservoir and attaching means (e.g. a hook) protruding from another end of the reservoir for attaching the strands of hair to said guide means. When the guide means is pulled out of the reservoir, the strands of hair to be treated are pulled in the reservoir through the first opening, and are treated by the composition therein. The implement is preferably ready-to-use.