TFR is traffic film remover, a sdegreaser used to clean cars/trucks etc, I already use that to clean conservatories, it works great, but still the ingrained mark, I know that upvc cream will clean it, but you have to wipe it on/off, hwich makes it hard to use on a roof unless you have the conservatory ladders... I just thought there may have been some kind off chemical that I could just spray on the plastic, brush to aggitate, then simply swill off, leaving a show room condition conservatory.