If it doesn't come out with any of the washings, tea dye it and call it "I did it on purpose". It would give it an antique-ish quality which would look pretty cool imho. :) I've used the generic "Goop" hand wash stuff , the lotion like hand wash stuff that comes in a tub, that mechanics use to wash grease from their hands.(also sold at Dollar General) and successfully removed crayon, marker, and other craft related stains from the girls school outfits.