Anything gentle will do...the peroxide should work or the denture cleaning tablets. Sometimes the glaze gets a little crazed or worn and that's when stains can seep in a bit deeper. Usually cigarette smoke residue is quite oily, even after washing....if that's the case and there is no danger of a design being damaged some smoker's toothpaste should do the trick.
If anyone is a collector of anything....and I mean anything. Do not allow smoking in your home, it's not just bad for you, but for china, fabric, paper, artwork.....most things in fact. I'm not a rampant anti-smoker, in fact I shamefully admit it's the one vice I can't seem to lose.....just do it outside. Saves a lot of damage and cleaning.