I do not know whether it is safe to use cocoa butter to flat iron your hair.?
I use shea butter after detangling my damp hair, and once my hair is set and air dried, I flat iron it. I use moderate heat so I have not noticed any damage. Instead my smoothened hair has less volume, it shines a lot and I have more defined curls and waves when my hair is damp. (note: my leave in is a small amount of curlaway and 2 tsp of jojoba oil and i just use cool water in a spray bottle to detangle my hair).
My 4b/3c hair drinks water every couple of days anyway. Water is what I use to make it soft. My hair is always in a loose bun and I wrap it at night.
If you don't like simple styles, you may want to do something that has a stronger loosening effect on the hair like keratin treatments or a texlax or some other natural relaxer.