What to do instead: Wash sharp knives by hand with warm, soapy water. Dry immediately with a soft cloth. Never leave them soaking in water (which can damage the handle and dull the blade).
Pro tip: Store knives in a wooden block or on a magnetic strip, not loose in a drawer where they can knock against each other.
2. Cast Iron Cookware (Destroys the Seasoning)
Why it’s bad: Cast iron requires a layer of seasoning (polymerized oil) to create a non-stick surface and prevent rust. Dishwasher detergents are designed to strip away grease and oil—exactly what you don’t want on your cast iron.
The damage: The seasoning will be stripped away, leaving the pan vulnerable to rust and sticking. The high heat can also cause cracking or warping.
What to do instead: Wash cast iron by hand with warm water and a stiff brush (use a small amount of mild dish soap if needed, but avoid harsh detergents). Dry immediately and rub with a thin layer of oil to maintain the seasoning.
