A few years ago I saw something about air sickness on BBC.
Some facility had developed a 3 axis revolving chair and first they would scan your head to get the exact layout of your inner ear and more importantly the little tubes in there.
They would plot this info into a computer, strap the patient into the chair and then very slowly rotate the chair around the layout of your inner ear tubes, thus making any large particles is the ear that can cause motion sickness to collect and exit the ear (somewhere on the inside).
It was a very harmless procedure and the subjects that were treated got cured.
I don't know if this is still in a testing phase or becoming available to the general public,
check it out,
I'll do a search on the net if I can find any more info (which probably explains the whole thing a bit better).
Cheers