I had similar problems when using either acetone or non-acetone nail polish remover.
(Also, people will tell you not to use the acetone kind because of vinyl damage risk. With a cheap barbie head, tho, I don't see much risk if you wash with soapy water immediately after. The thing is, if you actually soak vinyl heads in acetone they will swell up... and then they'll shrink! It also leeches out some of the plasticiser, making the plastic a little more hard and brittle. I intend to do this with a cheap or damaged head this summer and document the exact amount of shrinkage for study (I get called the Mad Scientist for reasons
Do not try my crazy at home...))
My current method for removing faceups is actually to use a dremel (well, off brand rotary tool) and a very light touch to literally rub/sand the paint off. It usually gives out well before the amount of pressure needed to start to sand into the vinyl itself. I'll admit tho, that that method is a bit extreme in some ways, but I like the control it gives me in that, if I wish, I can just remove parts of a faceup... like just some of the eyelashes for example.
This thread here (after a brief derail that got back on track) has touched on a few weird things to test out on cheap vinyl or other dolls. There are a couple other suggestions in there for stubborn faceups that I hope to give a try to myself soon.
viewtopic.php?f=13&t=11007I'm actually still part of the way into my first reroot... after days. I'm using the needle and thread method and can only work on it a few minutes at a time because of other demands and because forcing the needle through the vinyl makes my fingers sore. Still, it's going well despite my extreme slowness, and I can already tell the results are going to look great!