The Extended brush with one cane attached is used in Creature of Fenkenstrain. It is created by attaching a garden cane to the garden brush with bronze wire. Before it can be used it must be extended with two more garden canes, which are obtainable from nearby pile. This will produce the extended brush (2), and another cane will make the extended brush (3).
By using the longest extended brush with the fireplace located in the upstairs west room in Fenkenstrain's Castle, you obtain the conductor mould.