EQUINE VENICE TURPENTINE TO HARDEN & TOUGHEN SOLES Used on the sole of the hoof to toughen or harden the hoof in cases of soreness or tender footed horses. In this application it can be painted daily on the sole of the hoof and topped with brown paper until the desired results are achieved. Venice of Turpentine has also been used for its antiseptic qualities –in such cases it can be applied to rundown and other types of injuries.