Woks are made of cast iron or carbon steel, to avoid them rusting in storage manufacturers coat them with a factory oil. This oil needs to be scrubbed away before seasoning your wok. Seasoning your wok tempers the steel making it harder for better cooking and helps to make your wok partly non-stick. With the proper treatment, your wok can last for a very long time if not a lifetime. Avoid using vinegar or soap and the seasoning will improve with age. Do not ever season a non stick coated or Teflon wok. Using oven gloves is recommended.