This maybe happening due to product build up. If you are using products with silicones or mineral oil, they may require shampoo to remove them (which may be why your hair looks worse when you try rinsing with water only). It's just a guess, but it could be that!
My hair: 3b, corkicelli, medium porosity, medium texture, medium/thick density
Co-wash: DevaCurl NoPoo
Rinse-out: GVP Conditioning Balm
Leave-in: KCKT, Suave Naturals Coconut, or my rinse-out!
Gel: SS FHG (my new HG!!)... I also like HESMU, AIF, CJ CQ, BRHG, CJ PP and the occasional LALSG
CG and loving it!