Some of you mentioned co-washing made your hair feel greasy and the most common reason is using the wrong conditioner. After reply through several messages from here and FB I figured it'll be better to write it in a card, so all of you can use it as a reference.
My Top Cleansing Conditioner Recommendation:
Deva Curl No-Poo Zero Lather Conditioning Cleanser ($19.95)
Sulfate-, paraben-, and silicone-free! Best for color-treated curls since it delivers UV protection to hep slow color fading. Plus, it has a really refreshing citrus scent.
Shea Moisture Coconut & Hibiscus Co-Wash Conditioning Cleanser ($11.99)
Cruelty-free, silicone-free. This bottle is made for normal to naturally curly hair. It helps reduce breakage, hydrate hair and control frizz.
Matrix Biolage Cleansing Conditioner ($35)
No silicones, sulfates, parabens. Great for fine hair but avoid if you have extra-fine, thinning or oily hair. This cleansing conditioner is meant for uses in between traditionally shampoo.
Ouidad Curl Co-Wash ($36)
Made for thick, wavy and curly hair. This low-lather foamy texture is a combination of conditioner and oil that cleanses without stripping off hair's natural oil.
Living Proof Curl Conditioning Wash ($26)
Although they said this is for all curls, it's best for wavy hair. No-lather, no sulfate and frizz-free.