This sign reminds me of the sign "work." Sort of an
initialized version. Except I generally do the sign work with palm-side
of my left hand facing a little more backwards or upwards.
For the sign "use," the base of the right "u" hand comes
down on the back or side of the left "s" hand.
This sign is relatively flexible. For example, if you use a relaxed left
hand instead of an "s" hand--nobody cares. Heck, half the time
you just get rid of the left hand altogether and draw two small circles in the
air with the right "u" hand.