I've used dental floss to sew with in a pinch, but never for wrapping.  I'd say the unwaxed would probably be the best, though.  I really don't like using imitation sinew because I feel like I can't get it tight enough and being waxed, it seems like it wants to move around unless it's been glued.  That might just be me though.  I like real sinew because it shrinks and regular (heavy duty) thread.  I seal both with duco or super glue.  I've already said this in another post, though.  Have a great day/weekend.
Bowtarist says, "Play string music daily."