- Wide spectrum of soil removal. • Highly concentrated. • No unpleasant fumes. • Reduces labor requirements. • RTU—Ready-to-use. A pleasantly scented emulsion that utilizes phosphoric acid to quickly and effectively remove scale calcium deposits rust oxidation and other unsightly discolorations from bath tubs wash basins shower stalls drinking fountains toilet bowls urinals stainless steel and other acid resistant surfaces. RTU—Ready-to-use. • Sold as 12/Carton.