Short is the better choice - I effectively shorted these last year by writing options. Whenever I think oil is at a short term peak, I sell a call on UCO. I generally sell a front month call a couple of dollars out of the money. For that, the premium is good and I can still make money even if my timing is a bit off. At worst case, it gets assigned, so I'm short - which is better than being long.
If I'm unsure of the direction of oil, I sell calls on UCO & SCO at the same time. That way I collect 2 premiums, only one can possibly be assigned, and if that happens - I'm short.
I will do this stuff again when I disband my army of juniors - perhaps late spring.