I hates suave coconut as a co-wash. I always had oily roots as well and I do martial arts training for a couple hours a day so I was skeptical about the whole co-washing thing. I found that conditioner labeled as clarifying seemed to work best- my favorite is VO5 Vanilla Mint Tea. Make sure to massage your scalp well while cleansing and rinsing.
Cleansing conditioners are another option. They're designed to be gentle like conditioners, but they include ingredient designed for cleansing the scalp and roots (yes, regular conditioners have surfactants also, but in a regular conditioner surfactants are more incidental). I'm a huge fan of cleansing conditioners.

Modified CG since 11/5/11
CLEANSE: CJ Daily Fix, DevaCare No-Poo, CHS Treatment Shampoo
RO: SS Caitlin's Conditioner, CJ Beauticurls Strengthening
LI: SS Repairing Protein Treatment, CHS Silk Leave-In
STYLE: Re:Coil, Curl Keeper, Deva Ultra Defining Gel, Curls Rock Amplifier,Sweet Curls Elixirs Okra Gel and Hard Hold Gel, SS Curl Enhancing Jelly and Firm Hold Gel