I have also eperienced the rapid change towards positive buoyancy close
to the surface myself.  The wet suit that I am currently using is
particularly prone to this for some reason.  For me the magic number
seems to be around ten feet when the buoyancy thruster kicks in.
   I have found that dumping the air from my bc before ascending is not
quite enough to deal with this last ten feet.  Most bc's will retain
some volume, however negligible, of air in them when fully dumped.  This
expands in volume as you ascend and in my case is significant at the
surface.  To compensate for this I dump again right after my safety stop
at fifteen feet, which I do for most of my dive profiles, or pause and
dump at that depth if I am not planning a stop.  I've never tried your
kicking downward solution.
     Be wet and well.
Dennis
--- PCBoard (R) v15.21/10
---------------