Deleting Make Human MHX File Imports

I need to completely, cleanly, and quickly delete a Make Human import from a Blender file. The need arose because the skin texture does not render anymore, and so it seems I have accidentally corrupted the MHX import. I want to do a fresh MHX import. I find it is not simple for me to do.

In the Outliner Editor I did RMB on the root of the import’s hierarchy and in the pop menu selected the “Select Hierarchy” item. I did RMB once again and selected the “Delete” item. My expectation was that the entire hierarchy of the MHX import would be deleted. But it was not the case. In its place there were many objects from the hierarchy’s first level that appeared.

I did Ctl Z to undo the deletion and this time, after selecting the “Select Hierarchy” menu item, I put the cursor in the 3D View Edtor and deleted with the X key. The result was worse. An endless list of objects appeared in the Outliner Editor all prefixed with WGT.

Is there a way to quickly put the Blender file in a state it would be in if the MHX file had never been imported with a single deletion?