Coffee has been pointed out as a great substance to use when cleaning a kitchen sink.The Examiner has offered a number of tips on how to ensure kitchen sinks remain in great condition and pouring coffee down a sink is the number one method it recommends.This is because it is an alkaline substance that can help to dissolve any obstructions stopping sinks from functioning properly.Shawn Landis of the Examiner wrote Maintaining the appearance of the kitchen sink can be difficult as dishes will be washed here and many glasses of water filled.Over the winter months, material has built up in the pipes, unless the homeowner performs maintenance tips such as emptying unused coffee down it.He went on to say that hot coffee works better, but cold coffee or other alkaline substances can also be effective.Another kitchen sink cleaning tip from the website is to use baking powder to remove stains.