If the lines get to deep get some PDO threads put in, they stimulate collagen production and dissolve. Totally erased my "11" lines. Botox will not fill collagen deficit.
Overall I think the chances this would be successful would be very low, and the risk would be very high. I agree that structure is mostly based on width of hips and clavicles. There is only so much you can do to change how you look.
You can use botox in any muscle, wether or not it will give you the results you want is entirely different.
You would need large doses and as its an off board procedure you really want to make sure that's the only route left available.
Just my view.