Clear media caches manually when rake tasks fail

I’m in kind of a weird predicament. I’m running with Docker. I wanted to generate the new secrets for v1.5 but the rake task failed with an “out of space” error. Thinking that the issue might be in media caches, I tried to run the remove_remote and remove_silenced rake tasks, but they failed with the same issue.

How can I manually (safely) delete some media cache files? I just need to remove enough to let rake tasks run.