Ok so I just got back from a rather old Apple tree with 2 limbs. Removed the bark and scrubbed them with some washing liquid.
Will wait a few days for them to try on a radiator then bake them for a bit to make 100% sure no nasties are in the wood. If its a success with Dicky i will probably replace all his perches with various sizes as they are so much prettier and probably better for his feet.