Naphtha ... (Ronsinol lighter fluid). Don't "soak" the cloth, rather, dampen the cloth with naphtha. Don't let it soak, just wipe the crud off, and scrub a bit if you have to. You don't want anything wicking down into the fret slots. The last step should be to use a soft cloth dampened with some soap and water to remove the traces of crap that remain (the naphtha will mostly evaporate, but leaves behind a very thin film of whatever crud it was cleaning), followed by a water-only cloth (to rinse off the soap film). I'm in the "don't polish ... ever" camp ... most polishes suck and leave behind a waxy buildup, or worse, leave behind a film of silicone. You might consider a light dressing of the fretboard with Fast-Fret if it seems dry.
It's still gonna stink like tobacco, I'm afraid. Try making a sachet with some baking soda and letting it sit in the soundhole. Replace the baking soda once a week or so until you can stand the smell again. Some have success with Febreeze, too.
