How do I know whether the surface is sufficiently dry after treatment?

Respect a minimum drying time of 12 to 24 hours while ensuring sufficient ventilation. Afterwards you can use the surface again.

When in doubt, use a cotton cloth and rub an inconspicuous area. If no oil sticks to the cloth, the surface is sufficiently dry.

However, wait until day 5, until the oil has completely cured, to clean with water for the first time. Until then, be careful with liquids.