has anyone tried to use burnt oil (from car, etc). that is the old way of protecting wood. I have heard that this would be toxic for chickens but I do remember no chicken died years ago when I saw it and that was a good protection from lice and mites too.
the other idea is to burn wood but I don't know if it would be hard to clean.
the other idea is to burn wood but I don't know if it would be hard to clean.