With this wood burnishing tool (https://www.weaverleathersupply.com/catalog/item-detail/65-2961/exotic-wood-leather-slicker/pr_8725) inserted in a drill press, you can do a professional job of sealing the leather pores on the edge of a vegetable-tanned leather sole - particularly if you first wet the edge with water, then apply Toconole to it. Then turn on the press, insert the sole edge into the groove that is of the same thickness, and shine that edge!
By punching stitch holes and then burnishing the sole edge, this machine can turn a dream you might have of starting a local sandal-making business into a reality.
Have you ever thought of making and selling sandals? Do you think there is a market in your area for hand-crafted sandals?
Can you put a polishing wheel into it as well?