hello, how do you fix a double sided surface? One possibility - fixing my select and delete, but...

but this is my question - how do you fix it faster? In cinema 4D - I use MESH -> COMMANDS -> OPTIMIZE -> it deletes unused points, but it also merge polygon-twins. And in Silo I select in VERTEX-SELECTION Mode all points and I use Merge.

Is there a script for fixing that faster? I tried also BooleanCombine/Join it didn't works.

Screenshot:
http://i.imgur.com/EUVwdDT.jpg

I think I used im my case the mirror-command 2xtimes.