TJ I've done several bows with hemp cordage for handles, I've dyed it black with liguid rit dye and usually seal it with some diluted white glue
followed by several coats of spar varinish, and like ya say it keeps it grippy texture, leather looks nice but if it gets wet it also gets slimy.
Pat haven't tried the massey finish yet but I bet it also works good.
As for criticizing a bow as long as its done in a positive manner fine, but remember that a new guy posting their first few bows will be
extremely proud of their bow so with the criticism also find something positive to say about the bow. Criticism should also be offered
with advice as to why and how to fix the problem. If all your going to say is "Tiller is off" or such its best to keep it to yourself. JMO