I have a python code to delete duplicate geometry.. 

code snippet: 

gp.SelectLayerByAttribute_management(featureverticeshp_Layer, "NEW_SELECTION", gbgquery)

gp.SelectLayerByLocation_management(featureverticeshp_Layer, "ARE_IDENTICAL_TO", featureverticeshp_Layer, "", "NEW_SELECTION")

gp.SelectLayerByAttribute_management(featureverticeshp_Layer, "REMOVE_FROM_SELECTION", gbgquery)

gp.DeleteFeatures_management(featureverticeshp_Layer)

If you want I can provide the entire code (author name: Gerry Gabrisch). (I forgot from where I download it, but works fine with shape file).