Pour the warm water, dish soap, and apple cider vinegar into a bowl and carefully mix everything together, being careful not to let the dish soap foam up too much. Add the solution to a clean bottle.
Set your cat in a bath or sink and start to wet their fur with warm water.
Pour the homemade shampoo over their back and use your fingers to gently scrub the cleanser into their fur so that it reaches the skin.
Thoroughly rinse the shampoo out of their fur until suds no longer form. Be careful to avoid the ears, eyes and mouth.