Alternatively, the wick or scent-containing medium 5 may be made from a range of materials such as natural or synthetic fabrics, plastics or polymers, scent-impregnated plastics or polymers, absorbent permeable, porous or foamed elastomers, foam plastics, felt materials made of natural or synthetic fibers, or other absorbent or adsorbent materials, and in a variety of shapes and sizes to accommoda