Personally I think if you kept your fowl in the Bank vault in the Bank of England a fox would get in and kill them.
Human hair and piss doesn't work. Chicken wire can be bitten through. Fences can be dug under and jumped over.
A friend of mine keeps his fowl in an enclosure with buried wire and a seven foot fence. Outside of this he has a double strand electric fence.Beside this enclosure are his greyhounds. He doesn't seem to loose fowl to the fox.
Mind you, last Friday night he lost most of them to a Pine Marten.