Columbus Wax Stick

This wax stick from Japan works great as an edge polisher. It can be applied on directly by rubbing it on edges or some heat can be used to melt the wax for easy application.

You can also use this for waxing threads prior to stitching.

Tips: To create a more even edge, you can paint it in the desired color first and finish off with the wax for a glossy finish with some waterproofing and hard wearing properties 

https://www.youtube.com/watch?v=egq5mw1Hfgw&t=6s