Yup, it's easy to deglitter a pony and get their stubborn hair out of the head. Just soak the pony in acetone for 15 minutes. Just don't let it soak all day, I did that by accident and the pony got VERY squishy. I'm trying to get the glitter off a Royal Rose pegasus and I just soak parts of her in acetone for a while and BAM it wipes off. And getting stuck hair out, let it soak and wait till it the pony starts getting soft, it also softens the glue. Rinse off the pony, then yank out that hair!
~Jenn