Many wavies and long hair straighties conditioner-only wash and are sulphate and silicone free successfully. CG is largely about healthy hydrated hair, that has the potential to work for almost any hair type. CO-washing may not work for those with a scalp problem or those who have very fine thin hair who benefit from the 'pouf' that shampoo can give.
Wavies generally don't know their true curl pattern whilst using commercial products and standard techniques - brushing, combing, towel turbans and silicones can all pull out curl. It's more important to know your hair properties that your curl pattern anyway as that will help you choose appropriate products and ingredients.
It's worth working your way through the stickies on the newbies board and general haircare board, plus some of the articles on the main NC site especially those by 'curl chemist' Tonya MacKay. If you are still confused by properties you might consider having a hair analysis done, either Live Curly Live Free (cheaper but generic information) or Komaza Care (more expensive but very detailed).
Tonya McKay | NaturallyCurly.com
Live Curly Live Free - Hair Analysis
Komaza Care HAIR ANALYSIS Service - Rave! - Long Hair Care Forum
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
CO-wash: Inecto coconut
Treatments: Komaza Matani, coconut oil, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume, Inecto argan
Styler: Umberto Giannini jelly, Boots Essentials gel
Experimenting with: going back to basics