Review on Premium 8 Inch Nylon Tube Brush Set - 12 Piece Assorted Variety Pack by Julie Silva

I bought this brush to clean the inside of a guinea pig bottle. Why do they make it so difficult to clean these bottles? Once a week I wash these bottles and do my best to remove any algae or bacteria that builds up in the bottle. It's very difficult to do. Any suggestions on how to do this would be greatly appreciated. With these brushes I have found one that cleans the inside of the straw very well. The fact that the brush flexes is great as it cleans the straw as it moves in and out. However, it still doesn't clean the inside of the bottle very well. The narrow plastic opening makes this difficult. Now the easy bending of the brush isn't so good because you can't brush off bacteria with the easy to bend part. So in a way they're good, but in a way they're just good.