To polish in tight areas you might try one or more of the following
in your dremmel:
Wheel bristle brushes (small ones), end bristle brushes, small felt
wheels or points, small muslin wheels, a tooth pick (you may need to
wrap tape around it to fit your chuck), Bamboo Skewer (this works
like the tooth pick however they last longer and are about 3/32" in
diameter which fits the handpiece of most flex-shafts), wrap cotton
around an old bur ( a 0.5 mm round bur works real well to fit into
really tight spaces), a cotton swab, or cut a small cardboard disk
and mount on a mandrel.
Also, remember any item you buy can be modified to fit your
situation. For example, cut a felt wheel with a knife or trim the
outside rows of bristles on a end bristle brush with scissors. Cut
the bristles to form a pointed end. Then it will be easier to reach
into tight places. You can also cut away the center bristles in an
end bristle brush forming a small cup bristle brush.