Just wash the entire knife with hot soapy water, then shake it off the best you can. If you don't have a quality metal oil such as Militec or Tuf Glide (mineral spirits) you can lastly spray the knife with WD40 and wipe off all the excess. That should be good enough. You don't need to polish it unless you have light rust or corrosion on it. If you do, you can buy Flitz or Maas which are both good.