As a teenager, I figured quickly that dish detergent and hot water was the best way to clean a cap and ball revolver of most of the grime. It's important to dry it well. I would not want WD40 residue in the chambers fouling the powder.
My non-black powder guns do not get the water and soap treatment.
The idea of gloves is worth considering. Whenever I handle a gun, I wash my hands well. I am concerned about the cumulative effects to lead residue.