Idk, I think blowdrying after co-washing would defeat the purpose of co-washing. I always thought that you co-wash to infuse your hair with more moisture, so blowdrying afterwards would be counterproductive.....i think lol, imo.
I always airdry after I co-wash and I think airdrying as often as I can has greatly improved the condition, texture, thickness and manageability of my hair.