what are 2-double sided polygons

[Shadowth117]

You may be able to select all of the polygons inside the characters if you use the editable mesh modifier's polygon selection and use the ignore visible edges setting. If you set the planar thresh right, you should be able to select all of the polygon inside the model and delete them.

Alternatively, if they're not separated into too many different elements it may be better to use the element selection to select the polygons inside the mesh and delete them that way.