I don't think that Linseed oil is a good idea. It can go rancid and
"easily oxidized, and rapidly becomes rancid with an unpleasant odour unless stored in the refrigerator. Even when kept under cool conditions it has a shelf life of only a few weeks. Oil with an unpleasant or rancid odour should be discarded. Rancid oils contribute to the formation of free radicals and may be carcinogenic. Oxidation of flax seed oil is major commercial concern, and antioxidants may be added to prevent rancidification."
I would try to find the stuff they use to finish bamboo flooring as long as it's okay to be around food.