Bottle Cleaner Brush with Long Handle for Narrow Neck Smaller Diameter Bottle Openings. Silicone allows for the narrow bottle brush to be ultra-durable and long-lasting. The bottle brush is temperature resistant and can be sterilized in boiling water. Easy to clean, does not absorb water, rinses with tap, cleans and drains quickly. The silicone brush head is soft and does not scratch the container. The bristles are flexible and tough, do not fall off, break and can be used for a long time.