Loofah soap pads have two complementary functions: the soap is always dry because the soap and water residue that runs off collects on the underside of the pad. This is where they are used again: when cleaning the sink.,Loofah soap pads have two complementary functions: the soap is always dry because the soap and water residue that runs off collects on the underside of the pad. This is where they are used again: when cleaning the sink.