Coffee cup stain remover. Rub moist salt inside cup. Using gloves, rub the surface with lemon juice and salt. Soak in white vinegar. One-half cup borax in one gallon hot water disinfects common bacteria.
Prevention is the best medicine.
Once a week, plug the overflow and pour a quarter cup of baking soda down the drain. Follow with one-half cup of vinegar and cover tightly for a minute. Flush with two quarts of boiling water. Compost and vermicompost at home. Fleas on your pet.