Removing the smell of onions from hands and equipment is hard. I have found a bar of soap, that strangely enough is made of stainless steel. The smells are ionically attracted to the stainless steel, and are removed from my hands, cutting board, and knife. Once moved to the stainless steel, it is easily washed down the drain. This bar is hollow, to reduce weight, and it allows this bar of soap to float if dropped in the water. I like this bar, but a simple piece of Stainless Steel should work just as well. I have no affiliation with wonder bar, or it's parent company