I like paper towels. I use them to not only remove some moisture, but I find that it smoothes out the cake and it does become rock hard. Of course I like a thin cake as opposed to thick one. (dime v nickel thickness)Put me down as a paper towel advocate too!
I use the paper towels if the bowl seems to be gunked up a bit and usually use them only when the bowl is warm. It helps in the smoothing.
That's my inflation adjusted 3 cents worth.