The disavow tool is a very popular SEO/webmaster product from Google these days but don't be mistaken, humans at Google are likely never going to look at your disavow file manually. Google says that generally they are processed completely automatically.
Google's John Mueller wrote on Twitter, "the disavow files are generally processed automatically, no humans involved."
It is true that humans at Google review each and every reconsideration request by hand but not the disavow file. However, Google still says with manual actions (not automated algorithms) they want to see effort in manually removing links and not just disavowing links.
In any event, if you thought Googlers reviewed your disavow files manually, generally you are wrong.
Forum discussion at Twitter.