Deep cleaning is a thorough home cleaning where all rooms are cleaned, including areas and surfaces that are typically overlooked during regular cleaning. Deep cleaning is often done once or twice a year, such as in spring and autumn, to refresh the home and remove accumulated dust, dirt, and allergens.Deep cleaning is a thorough home cleaning where all rooms are cleaned, including areas and surfaces that are typically overlooked during regular cleaning. Deep cleaning is often done once or twice a year, such as in spring and autumn, to refresh the home and remove accumulated dust, dirt, and allergens.