Handwashing products to keep your hands clean and to take off hard-to-clean materials like oil and grease. These products are specially formulated in order to be used by mechanics. They have extra tough cleaning properties including solvents to remove grease, oil and ingrained dirt. They also use exfoliating granules to help remove stubborn dirt and stains. Working on cars is a pretty messy affair. Lots of dirt, grime and oil can build up on the engine and wheels and when working on the vehicle this then gets onto your hands. A general use handwash will go some way to cleaning the dirt off, but if you work on cars regularly it would be better to purchase the handwashing products which are made especially to remove dirt and grease without damaging your skin.