For super-emergency care of dry, cracking skin, the best thing I've found is pure lanolin. It's a natural oil derived from sheepskin, and reported to be nearly chemically-identical to human skin-oil. It is thick and sticky like pine-sap, like concentrated vaseline. Best for overnight treatment, with latex or plastic gloves so you don't get it everywhere.
I used this to good effect when I had deep cracks in my fingertips from using harsh cleaning chemicals on an espresso machine without gloves.
And Lee makes a very good point. If your fingers are bad enough to need this stuff, then they absolutely need time to heal without adding further stress.