Metal appliances can produce different degrees of oxidation over time, whether it is iron, silver, or inert gold. High-purity gold can also lose its luster when worn for a long time, covering the surface with other impurities.
We soaked the cobra buckle in thick salt water for 48 hours, allowing it to corrode and oxidize. After trying various methods to clean up the recovery fastener, finally found that the "grinding silver rod" is very effective. The silver bar has two sides, the thick side is used to grind off the oxides and stains on the metal surface, and the thin side is used for polishing. After polishing, it's refreshing!