How to remove unneeded languages from video files using ffmpeg?

I have a number of video files (500+) with lots of audio and subtitle streams for languages that I don't need and would thus like to remove to conserve storage space. I tinkered around with ffmpeg, but removing streams by processing one file after another turned out to *very* time consuming. Had no luck with scripting either as the video files contain different streams in different orders, which makes removal via index difficult and error prone. **There must be a solution that is both faster and also works for files containing different streams, right?** Any help would be much appreciated.