Slow draining water in the kitchen sink is usually caused by the gradual build-up of fat and food debris. If not treated regularly, this build up will eventually harden to cause that dreaded kitchen plughole blockage. Buster Kitchen Plughole Unblockers mighty one shot granules target food and fat build up. Whether its a full blockage or slow draining water, Buster gets to work quickly to leave kitchen plugholes free flowing again.