Thanks to @nightpool@cybre.space for this #mastoadmin tip:
When witches.town goes down in the next few days, you may notice Mastodon running more slowly, as Sidekiq workers try to contact it and have to wait for the request to time out before they can move on to the next job.
To handle this, AFTER w.t goes down, log into your server on the back end, run `redis-cli`, and enter:
sadd unavailable_inboxes https://witches.town/inbox
This tells Mastodon not to bother trying to talk to witches.town.