There are no issues with the operation. I have only used it for coffee beans. I have cleaned it as much as possible with the included brush and paper towels, but some coffee bean residue remains. If you are concerned about this, please refrain from purchasing. Shipping will be via Yu-Yu Mercari Bin or Raku-Raku Mercari Bin. I have had several cases where purchases were left unattended and subsequently canceled, so I will not accept purchases made with convenience store or ATM payments. Thank you for your understanding. Thank you.