Seal lath bindings, what to use?

I was intending to use hemp twine to lash the prod to the tiller on my current project, but, are sisal or jute viable alternatives? I have read Mac's thread from 2012, but what is the best waterproofing material for the lashing as it seems melted beeswax is not the best solution? Also, I had intended to use linen thread for the bow-string; does this need waterproofing too?
Thanks,
Andrew