A strange oral fixation!(long query)

[avpinc@bellsouth.net]

Hi y'all!
    Wanted to put this problem on your plates and see how you
would deal with it.  My horse, Johnny , the TWH/Racking Horse
is coming along as a trail horse really fine (with the occassional
lapses into sillines--all pretty normal stuff), and we have a great
time except for one thing.  Before I bought him he'd developed
the habit of putting his tongue over his bit.  I don't think, now,
that it is a really evasive technique, as I have him a a pretty
easy bit, although it could have been before as the previous
owners had him (as my trainer/instructor put it) in a bit that
would stop a Rhinocerous.  He's a very good natured horse,
but he does have plenty of pep on the trail, and the woman
who rode him before me was intimidated by his size and
spirit, so she may have yanked on him a lot.
     The point is, I've already had a pretty close call because
of this habit.  I've tried tightening his caveson, to no avail
I tried a flash (figure 8) noseband, tightened to it's max.,
but that didn't help--in fact that made it worse.  I tried
a rubber bit port on his bit, which he treated like a pacifier
and proceeded to chew to bits by pushing it sideways.  At
that time, I had him in a bit with a tongue port (the first thing
we tried) and I thought the shape of the pellham bit with the
port was not conducive to the rubber bit port staying in place.
I now have him in a straight pellham with a new rubber bit
port attached, and thought it was working great until he got
his tongue over it--fortunately we were just getting home
from the ride, and going through our gate when the tongue
appeared out of the side of his mouth, so that was a real
improvement--although he had managed to push the rubber
port over enough to get his tongue over and start to chew
the rubber again.
     Has anyone had success with any other techniques?
I won't consider "tying down" his tongue--I'll go to a
hackamore first!  Is it possible to put two of the rubber
ports on the same bit, side by side?
     This sounds like a silly problem, but it really can be
a disaster waiting to happen if not dealt with.  I'd appreciate
your input.   Thanks.  Linda in O.B.FL