Here is a AFA Deburring Tool (12mm hex) holder for the popular Gridfinity storage system.  It's a remix from the 1x1x3 bin and is set up to accept 6mm x 2mm magnets.  This utilizes a spring/friction clamp to hold the tool firmly.  You may need a drop of superglue to hold the magnets into place.

Print Settings:

• Print in PETG, ASA/ABS, or Nylon (the print needs to flex so the container will be grasped firmly by the spring clamp)
• 0.2mm Layer Height
• 3 Perimeters (1 Perimeter Bottom & Top)
• 5 Top & Bottom Layers
• No Supports Required