I love big showers with stone tile but the rough texture makes them so hard to get clean. I mean really clean. I had run across an idea using a small kitchen scrubbing brush on the drill and gave it a try. It did make cleaning easier, but that brush was small and the bristles soft. When I found this set of two brushes, I was pretty excited. And I wasn't disappointed. The flat brush cleans more area quicker, and the rounded brush gets into corners really well. No more scrubbing with a toothbrush! The bristles are stiff which means they work well to get into groves and impressions in the tile, including grout lines. But they aren't so stiff that they could damage more delicate tile. I highly recommend this set!