I exhausted every resource I could find, and came up with only one answer: unclutter
It is a small utility that will hide the mouse cursor after a small period of inactivity. It will not work on the root window, however. Also, it is probably not ideal for a touchscreen since the cursor will reappear with any movement/buttonclicks. In the case of my "embedded" app, the mouse is never used. Hope this helps.
