If it doesnt need to be natural you could try hypocare spray or Leucillin spray which ever you cab get. They are both great for helping dry skin.
Get them to ball up and spray on the quills once or twice a week depending how bad it is.
They are both known to have mo real smell. And dont need anything else doing other than a bit of spray.
I cant comment on the cbd oil though. I have no idea if thats safe or not.