My dad was a mechanic by profession when we came to the states in 1959, so he also worked on his car, scooters, motorcycles, and other peoples cars for extra money. He was the blue collar guy back in Holland when all his siblings were "professionals" of some sort. So to make his hands/fingers less "mechanic looking" he was prodigous at cleaning up after a project. Back in the mid 60's it was Lava hand soap pretty much. But not dad, he used Mr. Clean right out of the bottle with a rigid short bristle scrub brush, under his nails, tops of his fingers, he'd scrub em hard, complain about the sting, yet he never got an infection from the numerous cuts his hands and fingers suffered.
Kind of stuck with me too, I make it a point to scrub up my fingernails after some grimy work. Maybe leave just a tinge so people know I work wiht my hands, nothing wrong with that. I recall an interview with Sir Anthony Hopkins about his role playing motorcyclist Burt Munro for the movie "World's Fastest Indian" (great movie by the way), that Anthony purposely worked grease into his skin and fingernails for the role to make it looked like he really wrenched on his bikes, and its one of the first things I noticed when watching the movie.