Simply use a damp rag to rub clean, then dry. If needed, use a diluted solution of water and mild dish soap on a rag and wipe dry.
This is not necessary but if you would like to re-oil the case later you can use boiled linseed oil.
The natural finish will patina with age and look better than ever!
**Please keep in mind that moisture used on the black bezel may cause the black dye to run, and oil on the inner suede lining of the case may stain.**