If you use disposable bottle liners for freezing breast milk, they may require additional protection to stop leaking and contamination. (verywellfamily.com)
You can use disposable bottle liners throughout the day so that you only need to wash your bottle at the end of the night. (wikihow.com)
Don't store breast milk in disposable bottle liners or plastic bags designed for general household use. (mayoclinic.org)