Update to my 5 star review: only 3 of these brushes are useful for cleaning lime off my vaporizer but the rest are so soft they鈥檙e useless, so I can鈥檛 see the, working for grout either. Of the 3 useful brushes, all of the bristles are either squashed and spread-out or rusty from unsealed wires in the brush head. I鈥檓 only giving 3 stars because some of the soft brushes can be used for cleaning things like the threads of blender cups.