eddie, I have never used white vinegar before, but I did use the white vinegar and some hydrogen peroxide and wow....It didn't take that long before I started seeing the date....One nickel was being very difficult and I had to soak him over night, but the other 2 took a couple hours and they were done.
Sorry I did not mention it before, but if using white vinegar due not soak overnight. Check every couple of hours until you get to where you're going otherwise it will etch the coin surface. This actually does more damage to the coin and creates a frosted effect that you do not want to happen.