Yes this will be fine. In fact this the best way of running in electric motors in model cars and planes. Just make sure that you dry it out completely before it gets stashed away in some dark place.
off topic:
why do you want to do this?
(just curiousity)
Haha, well my fuel pump sits low down near my transfer case. I went 4wd on the weekend through some deep muddy puddles that would have submerged it (was in my other 4WD diesel). So was wondering when i finally take the Bundy wheeling the pump will be okay in the mud puddles.