I've left my lips alone for almost 8 months. I have seen slow, but steady progress and am thoroughly convinced I am on the right path.
In my case, I believe excessive use of chapstick was the primary cause of my condition. I think initially I probably had dry lips because I wasn't drinking enough water - which led to my constant use of chapstick and so on.
I would say that I am not convinced that not letting your lips get wet is the best thing to do. I think some moisture from water and steam is natural and thus an okay thing. The key is to do your best not to peel off the skin while they are wet. Just let them air dry.