rabbits pooing on blanket/fleece

they poo on them all the time and make them all mucky :roll:
is there anything else i could give them instead of a blanket(thats cosy)?

Have you tried litter training them as then they'll go in one place (not on the blanket) and make it much easier to clean out

Do you mean fecal pellets (dry) or cecals? Fecal pellets shouldn't leave any mark, they should just brush off, cecals you shouldn't be seeing although some rabbits, like my lops, tend to leave some marks when they are a bit sleepy.