I have to agree. I take my swivel knives up to 6000 grit (japanese water stones). Stropping it after each stone I use until I get to the 6000. I have heard of the use of flitz, but I have not tried it. I use black, red and green rouge. You cannot go wrong with a sharp swivel knife. it will help your leather carving by easying up by allowing the knife to glide easier.
Good luck