It's what I hate most about cooking, having odors left in my hand after chopping up onion and garlic. Good thing I discovered a neat trick to removing these odors from my hands at QTV, something that wouldn't require lots of soap.
Wash your smelly hands while holding a knife under running water (sort of what you do when you're rinsing a knife). Something about the chemical reaction of the water with the knife also gets rid of the bad odors on your hand.
I have tried it and it works. You may need some soap still but not as many washings. I am not sure though if you can get the same effect with other metals such as spoons and forks.