GROUT CLEANING BRUSH SET OF 4 SLIT SLITS FOR WASHING AND CLEANING WITH HARD BRISTLES. Product Description: We present to you our versatile Nikcorp Hard Bristle Gap Cleaning Brush. It is not only a tool, but a comprehensive solution for every household. Ideal as a crevice cleaning brush, it is perfect for small spaces such as bathrooms, kitchen sinks, and window seams.