You never said if it was counted cross stitch or transfer pattern cross stitch - if it is counted cross stitch I would say you could wash it, VERY GENTLY, and with the transfer pattern cross stitch, yes, freeze it, pick off what you can and continue sewing until it is done, put it all together and then wash it. I am working on a transfer pattern cross stitch Christmas quilt - have been for about four or five years now - billions of little cross stitches - and it is as dirty as sin. I am not washing it until it is done, put together, hand quilted, binding on and totally finished. Then I will wash it - in about 50 years. Good luck to you. It'll all come out in the wash. Edie