Here's my first attempt at focus stacking using the rail: A random potted plant. Being able to compare this to not using a focusing rail, I can say that this was a whole lot easier. I shifted the camera about a third of a millimeter between shots and then stacked it all using Hugin[e] and Enfuse[f]. The Enfuse command line was
--exposure-weight=0 --saturation-weight=0 --contrast-weight=1 --hard-mask --contrast-window-size=9. As you can see, it didn't quite get rid of the out-of-focus areas; they can be seen as haloes around the buds. It does give the shot a very dreamlike appearance, though.