1 cup chopped lemon, orange or grapefruit, including rind
1 cup baking soda
1-1/2 cups water
Mix ingredients, then pour into an ice cube tray. Freeze until solid. Remove cubes from tray, then place in a plastic bag if you are not going to use them immediately. Label the bag, and make sure the children don't get into them. When ready to clean the disposal, turn it on, drop in 6 to 10 cubes, and let the machine grind them up. Rinse disposal with cold water.