@stefan That sounds right. The status remove query is here: https://github.com/mastodon/mastodon/blob/96ddf1d4820419a6b5367af022be5cf17526109e/lib/mastodon/cli/statuses.rb#L61-L72
It's possibly it only removes statuses that don't mention a local user, which would not be helpful. I'm not an expert on this tool though https://github.com/mastodon/mastodon/blob/96ddf1d4820419a6b5367af022be5cf17526109e/lib/mastodon/cli/statuses.rb#L68
My script is here: http://wiki.sixohthree.com/mastodon-cleanup.html