This is interesting, Doug.

No, I'm not going to steal your idea. I'm (mostly) retired!!!

It might be important to learn some about stiction: specifically, how
much relative motion is necessary to overcome it in a given situation
of materials, transverse load, surface finishes and lubrication.
The 0.1 degree you mention seems like a reasonable guess, but I'll bet
it is only a guess. The "answer" may be more one of displacement
rather than degrees; e.g., a 1/2" dia shaft might need more angular
rotation than a 1" dia shaft to achieve the same effect.

You might have to do that by instrumented experimentation. Doing that
might give you proprietary knowledge and a "leg up" toward selecting
the best method of achieving sufficient motion to do the job.

It might be an error to fixate on any given method (piezo,
magnetostriction, etc) this early. Better to understand what needs
doing before selecting a way to do it, even if your instrumentation
uses one of these methods.

Dither has been used for decades in gyroscopes, particularly laser
gyros, to overcome stiction -- or "lockup" in the case of a laser
gyro. Some of them use random noise rather than a fixed frequency.
Random noise (sort of a hiss, like escaping air) might be less
onerous in a shop than a whine or single tone.