My company moved to the cloud about a year ago and has implemented the sandbox capability. We used the sandbox initially to test our migration plans and cleanup steps before we went to production.
Now that we have been in production for a while, I have cleaned up duplicate fields and other data. However, when you copy data from production to the Sandbox, all the legacy data on that site remains. I don't get a clean copy from production to the Sandbox.
There are several articles on how to clean/reset a cloud site, which in most cases consists of deleting the site and recreating it.
We created a custom URL for our sandbox site and had to remove it due to issues with application data.  It was a nightmare to recover the custom URL and to work with Atlassian for several weeks. 
So the question is how to clean up or remove legacy data from a Sandbox site, or to make it an option as part of the Sandbox copy to create a clean sandbox site. 
Hi @Brian Taylor
I am Adithya, the PM for Sandboxes. Please check out the "using the URL of a deleted sandbox site" under this support doc. Please use the "contact support" link under that section to request the "reset" of your sandbox. The reset operation will clear the data, but retain the URL. 
If you'd like to utilise this feature without having to reach out to support, please vote for this issue to help us prioritise this. Hope this helps! 
Hello @Brian Taylor
To get the newest data without it getting duplicated, you get the option to create the new site. Yes, ideally it would be to delete the data that was previously there to avoid duplicates, but not possible currently. As a workaround, you would have to create a new site to have the newest data copied from production.
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Nikola -
Thank you for the feedback. However, as I stated, we have a custom URL for the Sandbox. Per Atlassian documentation, if you delete the site, you lose that custom URL and cannot restore or reuse it.
I am not sure if it is possible to remove the URL before the site removal so that it can be reused.
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That's right, you need to wait for 30 days until it gets fully deleted, otherwise you need to use a different URL or restore the old one.
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