You’ll want to choose a food-grade oil, but that doesn’t mean the olive oil or avocado oil in your pantry as these can go rancid. Rather you want “polymerizing oils,” like linseed, walnut, or mineral oil, or beeswax, which will harden the wood as they dry. First, clean your wooden utensils, then use a clean rag to rub the oil evenly into the wood, and let dry overnight.