I had best luck with Tide. Had been wrenching before work, and hand to have hands spotless (medical). Hands were cleaner after washing than before starting work on my bimmer. Probably not the most gentle thing for the skin, and I Now lmow what [censored] fire feels like when a wrench slipped and I scuffed my knuckles. For anything else I gust use soap or dish soap. Grime is off by the end of the day.