if the other suggestions don't work - try these:

cigarette ash... sounds wierd... but many hairdressers swear by it. Have no idea if/how it works

baby wipes.. there is something in baby wipes that removes just about anything.

alcohol/turps - thus the reason perfume is suggested - as that is alcohol based

bleach or lemon juice.

But, if the dye has been on for hours - and/or you have really dry skin - then it will be difficult to remove, as the skin is like a sponge.