How To Clean A Dog Tag How Do You Clean This?

How do you clean this? - how to clean a dog tag

Recently ok now this dog tag, but he has not smoked, and now stinks / smells of smoke. If you know or a way to be clean and it smells better please help.
PS I have tried to put the dog tag in a glass of water, soap, lotion and body spray! I also have in my washing machine!