The light treatment is supposed to remove ball point pen marks. You use acne medicine and put the doll under a hot lamp for days, but if it's too hot, then the doll is ruined. I tired it with a Darci who had a black toe from being packed in newspaper print, but it did not work. I think the ink had moved inside the doll from tiny cracks. Darci is a 70's doll and so she is kind of old.
I bought dolls in second hand store (back in Canada) and they had a really strong smoke smell, I place one doll (Barbie) inside a Ziploc bag with a cheese cloth pouch full of coffee grinds (the left over after the coffee is done) I left it as is 2 days and when I opened it the doll smelled coffee and fortunatly this odor run out very quickly in natural air in a couple of days
this trick worked very well as well for a leather (suede) jacket, that got the strong smell of smoke from a BQ