I honestly have no clue. None of mine have fallen off with the hot glue yet, and I've passed several around to friends as 'testers.'
This is one of those things that seems like there's some secret way of doing it, but no one ever wants to say what.
If the hot glue fails for me, I'm going to try doing it the same way I do with the hot glue, except with Envirotex Lite to hold in the ribbon I use to hold the cap to the bow. It'll take a lot longer to dry, but it's worth a shot.