I think it depends on the product. Per keratin4u, the White should be applied after color & clarifying shampoo. Your way makes sense too, rather than washing out the color with the clarifying shampoo.
I did dry my hair to 80% dry per the instructions, and then flat iron.
Oddly enough, while I was waiting for keratin4u to answer my questions, I did some major googling to answer my own questions. I couldn't find any real product info or user experience with the White. Not even on the QOD website. I was going to order the standard QOD after reading everyone's experiences, then when I saw the listing on Ebay for the White, I just jumped on it without doing any research.