Once you use your carbon steel knife, wash it and thoroughly dry it. it is the best way to prevent it from rusting but it’s not mean that you wipe it with a dish towel. You should take great care to completely dry the blade with clean and absorbent cloth. Simply we can say that you should treat the carbon steel knife with any mineral oil and place it in a dry location and never think to put it in the dishwasher in order to protect it from rusting.