What can Bottle Brush Do? nylon bristles are durable and fine. It is flexible with an excellent bristle bend recovery. Our bottle brush an be used to clean a multitude of items, ideal for cleaning larger baby bottles, coffee pot and filter basket, sports bottle, cups, thermos, fish bowl, vases, blenders, water purifier, electric kettle and jars. Pls know that, our brush is not for small mouth bottles and narrow neck bottles, the opening mouth must be greater than 1in.