Deadly Mistake Numero Uno: Using a gel detergent or powered detergent that is old or has already gotten wet. The main tasks of a detergent are to remove soil from surfaces and prevent the re-deposits of soils on the surfaces. The best detergent formulations will be powdered. Do not use gels or liquid detergents. Why powdered detergent? Because in today's phosphate-free world, you need two types of cleaners in a detergent formulation to get dishes clean: 1. Enzymes to remove protein-based stains