How can I mass "remove empty snippet..."
 

I have been adding content with the csv2rw tool and found that I need to use the remove snippet... function a lot.

Is there a way to run this over a complete container with all the contained topics?

Yes, Create a view of the topics you want to remove all empty snippets from, this can be the whole realm. F6 (View Options) -> bulk pruning and you'll have two self explanatory options.

Brilliant, thanks!