After peeling onions or garlic, or working with fish, the odors will not wash off your hands even with soap.
To get rid of odors fast, just rub a stainless steel (not silver) spoon with your hands under cold water. After touching raw fish, you need to wash with soap and water to remove germs before you remove the odor.
Or, remove garlic odor from hands by washing your hands with lemon juice. This also works for fish and onions.
Or, you can get the onion smell off your hands by wetting them and then rubbing them with salt for a minute. Be sure to rinse afterwards. This also works for fish and garlic.