I spoke with the local head shop.
They claim the 'All Clear' shampoo works.
Missouri is not a med state, although there is a a bill working on it.
He may just have to let his chronic neck pain limit employment further. He already can't do anything to strenuous for very long.
if he fails due to the pain meds he may be able to show that his pain is a cause for disability ,ii wont be easy but it may prove his case,best of luck