I've never done the boiling water thingy, but I usually soak the sheath under hot running water for a few minutes then place it near a heat source till it is good and dry.
During the winter months I place it near (not on top of) a heat vent where the warm air can hit it....during the warmer weather months I like to hang it out on the back deck where the sun can do the job on it.
The sheath gets about as hard as I care for it to be...
I read on other forums about the melted wax process...the Scandi folks like to do this one....but I haven't tried it, and probably won't, as I believe the hot water trick does a good enough job for me....