Bulk delete unused materials?

I’m trying to cleanup a very complex scene, in particular the numerous materials that were created when I imported FBX files from max. Is there a way I can just delete every material in the content browser that isn’t applied to an actor in the scene?

Any news??

A trick is to just Migrate the Content folder into itself

So if you want to clean up ALL the unused stuff in the Content folder you can filter by Level, select the maps you want, right click => Migrate to another new folder called ContentNew, close Unreal, rename your Content folder to ContentOld and rename the ContentNew to Content again, reopen Unreal.
Migrate selects only all the assets used by that asset, and because it’s a level everything related to your game will be selected recursively and only the unused stuff will be ignored.

I can’t think of a way to bulk remove materials only, but bulk removing ALL the unused stuff is easy.

Note: When you package your game all the unused content is already removed from the .pak file.