Camellia Oil
After you finish working on your bonsai or other plants or trees, wipe your tools with this oil using a lint-free cloth. This will help to prevent rust.
Camellia oil is a natural product. This oil was commonly used by Samurai to help prevent rust and corrosion on their swords, and so has a long history of use. Although you should not use it directly on trees, it will not harm them.
Many bonsai growers also use this oil to help restore luster to their bonsai pots and give them a new life.
To learn about caring for your tools please read this simple article. How to Care for Bonsai Tools