This is a common problem among people with 4b/4C Hair types. Most shampoos contain sulfates which remove the real oils from your hair, leave it dry and hard. The only way to prevent this is to wash your hair less frequently and supplement oil and moisture into your hair when you do.
So you might want to try a less strong shampoo at first and then move to a more gentle one. A good moisturizing conditioner is a must, some conditioner will strip your hair of its natural oils. So look for one. Hence, if you want to keep your natural moisturizer and get rid of dirt and excess oils, 100% of the time you should shampoo your hair, you should avoid lathering up, and use a conditioner to wash your hair.
So you might want to try a less strong shampoo at first and then move to a more gentle one. A good moisturizing conditioner is a must, some conditioner will strip your hair of its natural oils. So look for one. Hence, if you want to keep your natural moisturizer and get rid of dirt and excess oils, 100% of the time you should shampoo your hair, you should avoid lathering up, and use a conditioner to wash your hair.