In my experience the people that wants to restore a destroyed instance outnumber the ones that want the instance scrubbed right away by 10-1 or so (if not more)

In my experience the people that wants to restore a destroyed instance outnumber the ones that want the instance scrubbed right away by 10-1 or so (if not more), so basically we (at another ISP) would decommission the instance (which could not be allocated to another customer) and leave a grace period after which it would be effectively scrubbed. If a user wanted to scrub immediately they could send a ticket and we would do it right away (this was noted in the "power down" email to the user), we saw very few of those.