How do you clean plastic canvas art?

Question:My sister made me a wall hanging using plastic canvas and yarn. I would like to know how to clean it without destroying it. It took her a long time to complete and it has sentimental value. I called the local dry cleaners and they said, "The plastic will melt." Well, DUH! If you have sucessfully cleaned a plastic canvas wall art, please tell me how. It is not on a frame of any type, no wood or cardboard backing...Mine is dingy and I would like to make it look better. Thanks in advance.

Answers:
Most yarn is washable, so I would think you could just put it in the kitchen sink or bathtub and wash it with Woolite or some other gentle detergent and lay it out to dry. Ask your sis what she thinks about washing it that way. Good luck!