How to remove unused materials from .blend file?

Hi guys. I’ve got a problem. My .blend file is too huge, it is 1.7gb but there are just few objects. I tried to find the reason of this. I’ve noticed that there are a lot of unused materials in my scene. I tried to save the scene and reopen it by Ctrl+Shift+O but it didn’t work. I even tried this addon: https://blenderartists.org/forum/showthread.php?233096-Orphan-Slayer-Clears-Scenes-and-Removes-Unused-Objects but when I use it, it says that there are 0 orphans so it deletes nothing.
I uploaded the file to Dropbox so you can download it and see what’s wrong with it. Thank you!
https://www.dropbox.com/s/v5ycw9iyaxjcpbj/Телевизор%20с%20Полкой.blend?dl=0

Hi Opahennessy,

Check whether there are Fake Users activated for those materials (F letter beside material name field).

1.7 Gb… I didn’t risk to open it… it’d be too much stress for my desktop.

Thank’s for you answer, I checked unused materials and they don’t use fake users so the problem still exists.

Thank you for your answer. I checked unused materials and they don’t use Fake Users so the problem still exists.

I opened it - which took some time - and found out, that no Fake Users are set.

Since you packed all data into the blend file (which isn’t bad), your file contains around 400 MB of textures. Unfortunately I have absolutely no clue where the other 1.3 GB come from.
Some stange thing I noticed: many materials got several (over 100) users, but none or only one of them is present in the file (no fake user!)… But this exceeds my knowledge

there might be more then one scene then !

happy bl

And how can I switch between scenes?

https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/3D_interaction/Datablock_Tools

You have a lot of groups in the file that are the users for various objects so they do not get deleted when file is reopened. You can see them in the Outliner if you set it to Group information display type and you can add them to your scene by shift+a -> Group Instance… . This is a huge mess. You could copy what you need to a new file - that would probably be the easiest solution.

You may also be sharing some Chocofur’s assets for free here by making the file available for download and this might be a litle bit illegal. You might want to remove the link.