Disable Material Duplication Anyone who has used Blender for a while has probably tried to duplicate a scene via Full Copy. They would have then found that in the duplicated scene, all of the materials were duplicated as well, receiving that infuriating .001 ending. Normally, one might be able to change all the materials back to the originals and then reload the file (as suggested here) to get rid of the duplicate materials. I can do this, but I have A LOT of material slots in my project, and the work is incredibly boring.

So basically, my question is...

Is there a button, script, feature, or anything else that would disable the duplication of materials when I duplicate my scene.

Note that if the answer is a script, I will need to be walked through how to use it as my Python skills are about a -52. :)
You can run this script to replace all duplicated materials in your file. Just paste it into the Text editor and click the Run Script button. 

It searches all objects, and then compares the first part of the material name (the part before the .001 suffix) with any materials named the same, and if a match is found replaces the object material with the matched material.

The idea would be to do a Full Scene copy and then run this script to remove all material duplicates.

import bpy
mats = bpy.data.materials

for obj in bpy.data.objects:
    for slt in obj.material_slots:
        part = slt.name.rpartition('.')
        if part[2].isnumeric() and part[0] in mats:
            slt.material = mats.get(part[0])


Before running the script, make sure your materials are named properly. Any material that ends with .001, .002 or 003, will be replaced by its "original version".

Credit for script goes to user liero on  this BlenderArtist.org page

Ctrl + Shift + O finishes the job by reloading the file.