I have seen this thread topic but haven't been following the posts until today.
Last night I was working on a negative that happened to be perfect for this technique. It is a shot taken straight up through the branches of a Magnolia tree. The branches and flowers were backlit and, on a #2 grade, the sky was paper white. A brief flash added an even, grainless, minimal density to the sky, vastly improving the print. I used the, "just yank out the carrier" method. This is a good technique to keep handy in a printer's toolbox.