Remarkable!  Some picture of the tool in use here-

http://centeringwithfiber.blogspot.com/2011/06/more-saori-woven-sandal-
straps.html">http://centeringwithfiber.blogspot.com/2011/06/more-saori-woven-
sandal-straps.html

I usually just work epoxy into my frayed laces and trim the ends, but this
is a lot classier.