If your kitchen sink isn't draining as quickly as usual, then it's worth trying a homemade remedy before you do anything else. Sometimes, dishwashing soap is your best mate here — this soap can combat some minor clogs.
How does dishwashing soap work on blocked kitchen drains and what kinds of blockages can it handle?
How Dishwashing Soap Unclogs Sinks
Dishwashing soap contains specific ingredients that target grease like detergents and surfactants. These ingredients break grease up so you can clean it off your dishes. For example, if you run a greasy plate under a tap, most of the grease will stay on the plate. The water won't affect its sticking power on its own. However, if you dip the plate in soapy water, then the grease breaks up and disperses so you can rinse it off.
The same principle applies to some sink blockages. The grease-busting properties of dishwashing soap are enough to break down the grease in some clogs. Dishwashing soap is also slippery, which can help some obstacles move out of a stuck position.
So, if your sink is playing up, try putting a few squirts of your dishwashing soap down your drain. Give the soap a few minutes to settle around any blockage and then flush hot water after it. If you notice a small improvement, even if the sink doesn't fully clear, then try the same process a couple more times.
Which Clogs Dishwashing Soap Works on
A few judicious squirts of dishwashing soap followed by hot water works on some problems in your pipes. Typically, this solution works best on blockages that are primarily made up of something that contains grease or fat.
For example, if you pour oil down your sink after using it or allow food to go down the drain, then these items can congeal together and stick in a pipe. A mix of dishwashing soap and hot water could eat away at the edges of the blockage and lubricate it. This could dissolve a small clog completely or it could reduce it so that it becomes small enough to move on down your drain.
If the stuff that is blocking your sink isn't grease- or fat-based, then the chances are that dishwashing soap won't work. If your sink is so blocked that no water drains away at all, then the soap also won't be much use — it won't be able to reach the obstacle to dissolve any fats.
If your sink doesn't improve at all after a dishwashing soap treatment, call your plumber. You may need professional help with your blocked drains.