I had a young LF Cochin who did the same thing with some thick nylon cord I had used to hang the feeder with. My son Patrick found her with a long piece hanging out of her mouth. He tried to pull it out and it did not budge, even picking her up off the ground with it before my husband Mike stopped him. Mike ended up cutting the cord as close to her mouth as he could and she swollowed the rest of it. We tried olive oil, and we talked to a vet ( we couldn't find one that would agree to see her). The vet said if the cord had been natural materials she would probably be able to digest it or pass it, but if it was nylon it would cut up her intestines as it got tangled up. Well we thought for sure she was doomed, but that was 4 years ago, and guess what? We still have her, and we never saw any rope remains in the yard. I am sure she had 8 to 12 inches inside her. I don't know if she passed it, or if she is still carting it around inside her, but it has never seemed to bother her. You never know with chickens, don't count her out yet.