Pouring baking soda and vinegar down your drain might not be the best idea for the reasons outlined above. But this affordable homemade solution can still come in handy when cleaning kitchen sinks and bathrooms.
Mix together a ratio of 1:2 parts baking soda to vinegar and use an old toothbrush to rub small amounts of the solution onto persistent stains and areas where you need to remove a build up of grime.