Instead using olive oil which is normally absorbed by the body, try using paraffin oil which will pass through the body lubricating the entire digestive system. This way your chicken won't recieve un-healthy amounts of excess oil and it should help her either poo it out or help you massage it and make her throw it up. Every morning and evening give her a really good massage in the crop kneading it so it doesn't clump together. Also, keep all grass short top avoid her ingesting fiberous material which will worsnen the problem. I once had a hen who decided she'd eat a hand-full of crusherdust so make sure there is none she can access. Good luck and best wishes,
The kid with some totally gangster chooks!
The kid with some totally gangster chooks!