I'm working on a site that was hacked in March 2019 and in the process, nearly 900,000 spam links were generated and indexed. After remediation of the hack in April 2019, the spammy URLs began dropping out of the index until last week, when Search Console showed around 8,000 as "Indexed, not submitted in sitemap" but listed as "Valid" in the coverage report and many of them are still hack-related URLs that are listed as being indexed in March 2019, despite the fact that clicking on them leads to a 404. As of this Saturday, the number jumped up to 18,000, but I have no way of finding out using the search console reports why the jump happened or what are the new URLs that were added, the only sort mechanism is last crawled and they don't show up there. How long can I expect it to take for these remaining urls to also be removed from the index? Is there any way to expedite the process? I've submitted a 'new' sitemap several times, which (so far) has not helped. Is there any way to see inside the new GSC view why/how the number of valid URLs in the indexed doubled over one weekend?