I had a 40-50 year old bathroom shower stall that was literally encrusted with scale that I couldn't remove with ordinary cleaners. It was dark, gloomy and moldy with a shower door that prohibited light and ventilation so, a hopeless case? Not so, the Grout Meister came for two days and transformed it. The blue tiles came to life, the new clear shower curtain brought in fresh air and light, and the entire bathroom became bright and inviting. The cost was entirely reasonable and I got more than a new shower, I got a new bathroom.