Lighter conditioners work best for co washing. And richer conditioners normally are best for ROs. But it's all up to you and what you think are light and rich conditioners. I think suave naturals are very light conditioners and tresemme naturals can even work for me to be used as co washers. For ROs, GVPCB is suppose to be a very rich conditioner (I haven't tried mine yet). I also use tresemme naturals and renpure organic conditioners as ROs. To me, it's really about what you want to use and what your hair needs. :]

I also agree with what everyone has said before me. I didn't start with the deva poo or conditioner, but i did buy a gel and curl creme. I don't use the same products everyday and have not had any problems with build up. I haven't noticed any gummy feeling from the current deva products I have either . They do make my hair light and fluffy though.
CG as of Feb. 2012
combination hair.
2c on top - low elasticity
3a&b scattered underneath - normal elasticity.
fine texture. thin density. A lot of it.
porosity: normal to high.
loves protein and moisture.
BSACV as needed.

products may vary. i'm a PJ.
loving Curl Junkie, Curly Kinks, and AS I Am.