Every so often a sulfate shampoo is a necessary evil to get rid of excessive buildup-I love Tressemme for curly hair.
I had the same problem w/co-washing, turns out low porosity was the culprit. Condish just sits on hair w/out absorbing.
The best solution is to dilute condish in a spray bottle to the consistancy of milk. Use just enough to detangle, plus it can double as a L.In also.
Honestly conditioning every single day is not necessary, a good saturating rinse w/water followed by a bit of L.I. on the ends only is plenty, followed by a styler. Hope this helps!