So this leaves the delicate question (since I know I am basically committing THE ULTIMATE SIN, in the eyes of you die hard collectors) of how best to clean my babies. For clad coins I use a rock tumbler with water, gravel, a squirt of Dawn detergent and a dab of white vinegar ( always separate the pennies to avoid pink nickels, dimes and quarters). As example, here are 2 of today’s finds: an 1891 V nickel and an 1857 Seated Liberty dime. What would you suggest I do? Many thanks.