I've heard that cinnamon/clove/peppermint oil can keep them away. Apperently fake fox urine can do the same thing. There are also a few plants that have the same general "scent repellent" properties. You should also check whatever you are decide is chicken safe, because it might not be. I did a little bit of looking, it seems like biologists microchip them. Paint/dyes are not safe, reptiles are especially sensitive to fumes and I imagine it could also get stuck between/over their scales.
While transporting to a new location is better then just killing them, the vast majority of transported animals die anyway. I'd still rather give them the chance, but just know it might be closer to snake heaven then we might want :/
I really appreciate you wanting to let the snakes live, reptiles are my favorite.