Everyone knows Google Search Console has a removal tool, they launched it back in 2007, so before most of you were into SEO. But did you know how long it takes for Google to remove a URL after someone requests removal via this tool?
Google said it generally takes less than a day for the URL to be removed. Google said on Twitter "this generally takes less than a day" but if you expect it to be gone within 30 minutes, Google said that is "probably a bit optimistic."
This generally takes less than a day, but 30 minutes is probably a bit optimistic :-). Hopefully the dev-site is now properly secured!
— Google Webmasters (@googlewmc) June 18, 2018
Deal is, even after you do the removal request, it only lasts up to 90 days. If you want it to be removed permanently make sure to use a 404 (Not Found) or 410 (Gone) HTTP status code on that page.
Forum discussion at Twitter.