unfortunately, you'd have to take over ownership then delete it. here squeaky noted "As always if you find an asylum that is inactive and you would like to take over maintainership, open a support request as there is a process to handle this." however that process seems to be ignoring support request for over two years, even if the community was yours or the journal associated with it was erroneously purged at ij's fault.
i don't think there are any add ons that will do that exactly, the only thing i can think of is going here and deleting the visible ones.