if you just try water preferably hot water if you can , let it sit for a minute hopefully it will start to turn a white and soften up and good blade, its still a nightmare, but should come of . if it doesnt complain and ask for the ones who fit it what to use and then ask for more money. had the same problem . just done the above.
i also fit it as well had this problem told the supplier they went out and cleaned it of as it was a faulty batch. changed to a medium tech film no problems since