Here is Jim verticutting #3 green at Leslie Park.
Here is the putting surface after vertical mowing. Not the organic matter and thatch.
After the mowing, we blow off the organic matter and thatch that is brought to the surface. We then spread a very light layer of sand over the green and brush it in. This brushing also has the benefit of standing up some of the blades of grass that the machine cut but did not lift. Then we mow the green. After a few days, you will not see the lines any more, but you will hopefully notice a smoother ball roll.