A stainless steel soap is a solid bar or pebble-shaped piece of stainless steel marketed as a way to remove strong food smells — garlic, onion, fish — from the hands. The user rubs it under running water as if it were a bar of soap. The claimed mechanism is that sulphur compounds responsible for the odours bind to the metals in the steel, lifting them off the skin. Chefs and home cooks who use them report mixed results, and there is little rigorous published evidence that the effect goes beyond what thorough washing with water alone achieves. Unlike real soap, it does not shift grease or kill microbes, so it is best seen as a deodorising novelty rather than a hygiene tool.