Mayonnaise is a wonderful conditioner, leaving you with silky, shiny, healthy hair. However, unlike commercial conditioners, mayonnaise doesn't rinse out with water. That's because mayonnaise is oil-based, and oil and water don't mix. Avoid greasy locks by getting the mayonnaise out with a little shampoo and elbow grease.
Step into your shower without turning on the water. While your hair is still full of mayonnaise, use diluted shampoo. Work this through your hair. Don't expect piles of soapy suds; this first step is just to cut through the oil.
Turn on the water and rinse out the first shampoo. Work the water into your hair, using your fingers, to rinse out as much mayonnaise as possible. If you have fine or short hair, or if you didn't use a lot of mayonnaise, you may not need a second shampoo.
Shampoo a second time as you normally would, working the shampoo into a lather. Your hair should slide through your fingers easily and feel conditioned, but not oily.
Gently comb through your hair to make sure there are no chunks of mayonnaise left. This step is especially important if you mixed your mayonnaise with another natural hair conditioner, like egg or avocado.
For shiny hair, finish off with a blast of cold water.
For hair that's especially damaged, use a bit of your regular conditioner after you shampoo.