Hey girl,
Thanks for visiting my blog. Yes, I do two strand twists a lot. When I do mine, I always do it on washed hair. However, I make sure that the hair has been dried a bit with a t-shirt. To keep it from unraveling I apply my whipped shea butter to the ends and then twirl my fingers around the ends. That always keeps it "locked". I have done my twists with dry hair and I also used the same method.
Regarding washing my twists, I have tried it before, but wasn't successful (
Discovering Natural: Co-washing my Twists). I do it ALL the time with Little Sis and her hair stays in tact. If I were to try it again on my hair, I plan to gather sections of the twists, put a ponytail holder at the base of each section, and another ponytail holder at the end of the hair. By putting it at the end, I think that will keep it from unraveling.
I hope this works for you.