In reply to neilnevill:
yeah a bit odd that...still it showed me what I wanted to know.
Rope was shoved loosely flaked inside a pilow case which I knotted closed, washed with soap flakes at 30C on the wool cycle, given an extra rinse then chainlinked and laid out on a towel on the dining room floor. Seems fine, still has it's middle marking and seems to be drying fairly well so thanks for the adivce.
I'll undo the chainlink tonight and just lie it flat for another day or so until it dries completely.