convert wet brine recipe to dry brine
We can quibble, but brining, by definition, is wet.  When there is no liquid, you are just salting or dry rubbing (although the term is popular, and few make the distinction).
It is unlikely that any oj, or anything other than salt molecules are penetrating the meat.  So, the oj is just a surface treatment, as is most marination. If you like the texture of brined pork, why mess with the oj brine?  I would use the oj brine, then right before grilling, use your spice rub without the salt.