I agree with the recommendation that some kind of oil is the way to go. However, I have some concerns about using "boiled" (actually, chemically enhanced) linseed oil compounds or tung oil compounds on knives that will be used to prepare food. In such cases, I use and recommend the food-grade walnut oil that one can find in health food stores or in large supermarkets. Walnut oil is nontoxic (though some people can be allergic to it), relatively inexpensive, and it polymerizes better than other food-grade oils like cottonseed oil, soybean oil, corn oil, olive oil, canola oil, or mineral oil. Thus, over time and after repeated applications, walnut oil will seal about as well and give the same kind of finish as linsed oil and its compounds.