It happens every so often, that one does not have water available. The Shulchan Aruch (Orach Chaim 4:22) addresses this issue and writes that in such a situation one should use a midi d’menaki – an item that cleans. The question is, however, how is this done? Does one merely wipe both sides of the hands, on the front and back? Or must a person also wipe in between the fingers?
Some Poskim have stated that one must wipe in between the fingers. When the question was posed to Maran Rav Chaim zatzal, he ruled that there is no need to do so.