The handles work quite well. No blisters with heavy work, stag gives traction/grip, guard and rounded/enlarged pommels keep the knife in the hand.

Rudy's designs were for serious hunters in the middle of nowhere, where failure was not an option. They were not things of beauty in his time, greatly improved aesthetics today, but in common, they plain work.

No idea as to black residue in your experience. The polished aluminum on the Ruana is squeaky clean, and only black will be from user hands.