Odour Neutraliser works by trapping and eliminating noxious odour molecules in the air, instead of merely covering them up. The block emits a pleasant bubble-gum fragrance. It is ideal for placing in internal ventilation systems to get rid of odours. To get a more powerful effect, take the block out of the tub, put it in the lid, and place it in the required area – this will increase the surface area of the block, enabling it to capture odorous compounds quickly.