This brush is super convenient for cleaning bottles, but it's bristles are extremely soft. They can exert basically no scrubbing action on anything as a result. Fine for light cleaning and soaping of things, but you will have a hard time removing anything dried or sticky with it.
I needed a brush to help clean tea and coffee stains from my mugs. This brush is just the right size and has bristles on the end which helps to get at stains on the bottom that I was having a problem with.