No matter how long you have been natural, you still may not know what co washing is, so I am going to quickly explain it.
Co Washing- In the shortest and basic terms is washing your hair with conditioner, instead of shampoo.
Most people will co wash their hair in between washes, especially if they only wash their hair twice a month just to "cleanse" their scalp as much as possible, without stripping it.
Shampoo tends to dry your hair out, as co washing will moisturize it and keep all of your natural oils intact.
It is obviously not going to cleanse your hair like a shampoo would, but it will provide you with some relief.
When co washing you can pretty much use any conditioner to get the job done, or you can use conditioners designed for co washing specifically.
I personally do not co wash, just because I like the feeling of a clean scalp and co washing does not do that for me.
Hope this helped.
Bare Your Hair