The whole idea with a frost free silcock is that the actual guts that shuts the water off is at the long end of the handle, way at the base. They comde in various lengths to accommodate different wall thicknesses. So, when you shut the water off, it is already way inside the wall so normally, an internal shutoff is not required. You MUST remove any hoses, so that the water left in the outer part of the valve can drain. The thing should be installed with a little slope to drain, but enough will to keep it from splitting unless it is sloped severely backwards towards the house.