Zep® Mold Stain and Mildew Stain Remover is a ready-to-use formula that quickly dissolves mold and mildew stains with the power of bleach. This easy-to-use formula allows you to spray and rinse surfaces clean. An excellent bathroom cleaner for eliminating dirt, stains and grime on toilet bowls, sinks, tubs and more. The professionally concentrated bleach level grout and surfaces whitened.