Not to be confused with baking soda, (sodium carbonate) is much more alkaline and effective at cutting through heavy organic buildup. The Method: Pour a cup of washing soda into the drain. Follow with boiling water.
For more stubborn blockages, you may need to use a plunger or drain snake: drain unblocker homemade
For clogged drains caused by grease and food particles, try using dish soap and hot water: Not to be confused with baking soda, (sodium