There is also a toothpaste called Topo smokers toothpaste. It is an excellent stain remover.
I had a yellow stain on my dentures pretty bad, found a product called stain away at cvs, one soaking took stain away white as can be now
You can buy a denture cleaner for smokers that helps the stains from tobacco. I have heard some people use diluted bleach to soak them in (make sure you wash them good afterwards)
Home cleaning for dentures