The only problem I had with mine was that it gummed up right away and even after I tried to clean it remained gummy. I don't think this really had anything to do with the brushes but the fact I hadn't cleaned my pipe in over two years so there was gunk on gunk on gunk. I even thought about naming my pipe Tony Gunk lol. I really loved the brushes.
I like them wish they had a bigger one..
They are CDC ery easy to use and even easier to clean.