Asperox Sparx Lemon-Scented Rock Salt, the newest member of the Asperox Sparx family, is designed for use in dishwashers. Rock salt softens limescale in water. Lemon-scented rock salt eliminates odors caused by residual waste in the machine and cleans the machine's filter. As directed, fill your machine's salt compartment to the maximum level with salt and tightly close the lid. Refill when your machine's salt indicator light turns red.