The most appropriate oil to use for a kerosene lighter is, indeed, kerosene. Kerosene is specifically designed for use in oil lamps and lighters due to its high flash point, which makes it safe for ignition. It is a flammable hydrocarbon liquid that burns cleanly and efficiently, providing a steady flame for lighting purposes. The flash point of kerosene is typically around 100-120 degrees Fahrenheit (38-49 degrees Celsius), which is well above the ignition temperature of most household materials, ensuring safety when used as a fuel source.

The use of kerosene in lighters is supported by its low viscosity, which allows it to flow easily through the lighter's fuel reservoir and wick system. This ensures a consistent and reliable flame. Additionally, kerosene has a high energy content, meaning it produces a bright, hot flame that is ideal for lighting. It is also readily available at most hardware stores and gas stations, making it a convenient choice for those in need of a reliable lighter fuel.

According to the U.S. Department of Energy, kerosene is a refined product of crude oil that is used for heating, lighting, and cooking. It is a non-toxic, colorless, and odorless liquid that is safe for use in lighters when handled properly. The American Lighting Association also recommends kerosene as a suitable fuel for oil lamps and lighters, emphasizing its safety and efficiency.

In summary, kerosene is the ideal oil for a kerosene lighter due to its high flash point, low viscosity, and high energy content. Its widespread availability and safety profile make it a practical choice for those in need of a reliable lighter fuel.