I use golden rods for throttle, they are fantasti for that application. Aother one might be Water Rudder in a seaplane. Other than that...
In modern applications the servos are usually VERY close to the surface, and a solid rod is the best solution. If you plan to put the Elevator servo in the center fuse sections, a solid 2-56 rod in a plastic sheat is my preferred solution.
Ciao
Beppe