I've seen something sold through several different catalog companies that is supposed to work. It's basically a piece of metal shaped like a bar of soap. I'll try to find out where I saw that and add something here.
Googling...
http://www.tipztime.com/area/kitchentipz/odors.html
To get the onion or garlic smell off your hands just rub your hands on your stainless steel sink, viola!! (Jean)
______
To get the smell of onion from your hands after cutting up an onion, simply rub a metal spoon all over your hands under water. (Linda)