I have a large black out curtain that covers patio doors. The white backing which is the plastic/rubber coating to stop the light go through has got grubby as the kids have run in and out with garden dirt on their hands. I have tried sponging it clean but it makes only a minimal impact on the marks.
Previously I have tried to wash them in the machine but the backing has stuck together and I have had to scrp the curtains.
Do I dry clean them? Or do I wask them in the bath? Suggestions please