I am talking about rubbing the mercy cream, not your dry skin!
The trick is leave your lips peeling, try to avoid something else like water to tear it off and use mercy cream often. Of course, when you just showered and your lips are wet. Dry it off softly with your towel. Don't rub it or brush it. But just let it touch your lips.
When it's dry apply mercy cream / ointment again.
Let me know, if it has helped you.
I'd like to know if it has worked for you too.