This product was expensive and ineffective. I assumed spending $14 on a shower cleaner would guarantee an effective product that would be safe to use on my grout sealer (also Bondall). The instructions say to leave for 24 hours, having done that twice, it removed hardly any mold, and took up a heck of a lot of elbow work. I also thought this would be more natural than bleach but i think i'll get myself a bottle of oil of cloves instead. The nozzle also driped half of the product down the bottle and over my hands. Never again!