Hmmm, I've had the same problem, though I haven't tried to fix it. I know back when I used shampoo I would add 1 1/2 teaspoons of olive oil to my shampoo if it was leaving me "squeaky". It never made my hair greasy.
rocking 2c waves with 3a bangs (on a good day)
Low-poo: Yes to Carrots (contains Sodium Coco Sulfate A.K.A. SLS), Live Clean Volumizing
Co-Wash: Suave Naturals
Rinse-out Condish: Yes to Carrots
DT and PT: IAgirl's PT, Enjoy Hair Mask (A-cone)
Stylers: Joico Curl Defining Cream/Gel
, Joico Joiwhip, He Body Envy Gel, He Tousle Me Softly Mousse, Boticelli Babes FSG, DIY sea salt spray