As you give the demonstration, be aware of the fact that they are getting the information from what they see and probably ignoring what you say.
Please note. The lacing goes from:
front to back (through the hole) (pic) and then again from
front to back (through the loop) (pic).
Watch the front to back orientation because it is a major part of the scoring criteria.
Hold the tool with the single cordovan stitch on top.
Say:
Release the tip and let the lacing fall down the back.
After about another minute, does the person complete three single cordovan stitches correctly?