at first, I was certain that you were using a script of some kind to hasten the find posts to report. that is pretty impressive(at least for me) it needs a lot of dedication to do what you do especially when you are doing it without using a script/s. I would not have that much patience or time to look for that many posts to report every day. I admire the work you are doing.
My methodology for reporting low-value posts excludes random searches. Because if I randomly went through various topics in search of posts, then it would take a huge amount of time. It would take more time to search than to send the reports themselves. Therefore, to save time, I always focus on a particular section and send reports exclusively from there, as long as they are there. Once the cleanup is over. I'm just moving on to another section.
For example, in December-January, I only reported this section:
Digital goodsWhen everything ended there, I went to the section
Invites & AccountsWhen this section ends, I will move on to another one. That is, if you do not use scripts, then you should use a systematic approach in order to manage to send such a large number of posts. With a random approach, this is impossible, I would never be able to send so much in such a short time.