The Professional House Cleaning Technician's ManualCleaning is such an integral part of our daily lives that we dont always think about its important role in the quality of our lives. Scientific advances in the areas of microbiology, chemistry and cleaning technology are redefining our understanding of clean and what it means to our health and well being. Homeowners used to be satisfied if their homes looked and smelled clean. Now they know that harmful germs can linger if not properly eradicated.