The sinks in a household are prone to clogs regardless of where they are located in the house. Bathroom sinks often clog with soapy buildup and hair. Kitchen sinks can be clogged with food, grease and soap. Utility sinks that are connected to washing machines can become clogged with lint, dryer sheets that have ended up in the washer and soap buildup. Ammonia can help to loosen the clogs so that they can be forced through with a plunger.
Pull up the stopper in the sink if the sink has one. Inspect the stopper for hair or other debris that might be stuck around it. If you find any debris, pull it out with your fingers. This will allow the ammonia to reach the pipes more easily.
Stuff any connecting drains or overflow pipes with old rags. This will prevent the ammonia from avoiding the clog and traveling a different route.
Heat 1 quart of water inside a 2-quart cooking pot on high heat until it begins to boil.
Fill a measuring cup with 1 cup of household ammonia and pour it into the boiling water.
Dump the boiling mixture into the drain slowly. Leave the drain alone and allow the ammonia mixture to sit over the clog for 30 minutes.
Fill the sink with 2 to 3 inches of lukewarm water.
Rub petroleum jelly around the bottom rim of a forced-air plunger.
Center the plunger over the drain and push the handle down 10 to 20 times rapidly. This will force gusts of air in through the water and break up the clog.
Remove the plunger and run water to make sure that it drains properly. If it does not, or is slightly improved, repeat the process to finish removing the clog.
Run cold water through the drain to rinse out leftover traces of ammonia and remove the ammonia odor.