I actually just did this last week as I posted on another thread with great results.
I used Cantu leave in and coconut oil which I piled on my hair that was sectioned into 4. I sat under the dryer for 20 min, and rinsed. I got better curls than I have ever gotten using any other products or methods.
Originally I had planned to co wash after the DT, but since my curls looked so good, I just went with it. I tried it again several days later with the same two products on wet hair and did not get nearly as good results. My hair was soft and I am sure just as conditioned, but my hair LOOKED better with the DT on dry hair.