This isn't meant to be overly negative, but exposing financial corruption is mostly about information control; I don't see how LLMs help much here. Even if/when you find slam-dunk evidence that corruption is occurring, it's generally very hard to provide evidence in a way that Joe Average can understand, and assuming you are a normal everyday citizen, it's extremely hard to get people to act.
As a prime example, this bit on the SF "alcohol rehab" program[0] went semi-viral earlier this week; there's no way to interpret $5 million/year spent on 55 clients as anything but "incompetence" at best and "grift and corruption" at worst. Yet there's no public outrage or people protesting on the streets of SF; it's already an afterthought in the minds of anyone who saw it. Is being able to query an LLM for this stuff going to make a difference?
[0] https://www.sfchronicle.com/politics/article/sf-free-alcohol...