Review on 🧴 Bottle Cleaning Brush Set for Washing Narrow Neck Beer Bottles, Thermos, S’Well, Hydro Flask, Contigo Sports Water Bottles and More - Long Handle Brush with Straw Brush, Kettle Spout/Lid Cleaner Brushes by Elizabeth Jackson

I bought these for clean thermal flasks that keep drinks hot or cold longer. They have a thin neck and flare out like most bottles do of course. The problem area for cleaning is the bottom of the bottle and the bristles of the brush are not very rounded at the top. The bristles at the very top of the brush are almost flattened, so I'm not sure it cleans the bottom of my bottles well. The picture before purchase shows the bristles with a nice rounded brush tip that makes it look like when you push it into the bottle it will hit the ground with ease. The green tipped brush is a lot bristier on top than the other one, but I'm still not sure it cleans the underside very well.