Do you have any connections to OR staff or current CRNA students who have shadowed before? When I was applying to school, I knew several other CRNA students who had worked as RNs in my unit, and they introduced me to the Chief CRNA at our hospital.
Even though your hospital doesn't allow shadowing, try to find someone to introduce you to the Chief CRNA or at least a staff CRNA in the OR, and they can probably recommend another hospital to go to. Your unit manager might even have connections to these people that are helpful. The anesthesia world is very small, and a CRNA in your OR will probably be able to find you another CRNA to shadow elsewhere.
My husband is from the Houston area, and there are a good number of medical centers to try, as well as outpatient surgery centers.
Good luck to you!