I finished the other willow box (the one which I made too small) with a pure beeswax finish; melting the beeswax until liquid and painting it on the inside which had been warmed with a heat gun. The wax sets quickly and the hot air gun was then used to melt it into the wood. The outside of the box was then waxed and any remaining liquid wax rubbed off; the box was then buffed.
I use the same technique with shrink pots and drinking cups, but if the cups fit into the my wax pot I just leave them to soak, turning them around occasionally.
I like this technique as the wax is soaked into the wood and does not just sit on the surface. Wax inside the shrink pots means that they are food safe and do not smell. Use Danish oil and the smell of the oil takes months to disappear. With my green woodwork items I am wanting to use natural finishes that can be made at home, it is a big subject and I do not have much time to research it at the moment, any recipes are gratefully received.