This is another easy and natural way of unclogging the drain. Bring 2 liters of water to a boil and add the dish soap. Pour the mixture down the drain. The mixture warms the grease clog to a liquid, allowing it to flow freely out of the drain.
Use a cup plunger to force the grease down the drain. If the drain is fully clogged remove the drain stopper and fill the sink with water. Plunge the drain hole using the same motion as you would with a toilet.