It looks a little like a short, yellow R2-D2, but the Karcher wet-dry vacuum is one of the most important tools in Alpha Cleaning Services' arsenal. With powerful steam extraction, it breaks up stubborn stains from fabric fibers and ousts dirt from carpeting in high-traffic areas. But the Karcher isn't the only machine stains have to worry about; cleaning technicians also accost them with rotary scrubbing equipment. These machines shampoo rugs with circular strokes, massaging in a kid-friendly, organic cleanser designed to leave carpets smelling as fresh as a talcum-powdered daisy.