wadding/ horse hair/similar for upholstery projects (Pickering YO18)

i am currently working on a couple of recycling/upcycling projects and running out of 'filling/padding/wadding'.
Contents of sofa cushions may be suitable as long as they are not foam.
My last find was an old mattress probably designed for a fold away bed which was full of hair/straw. Apparently its coconut fibre...
Anything considered.
Sandie