"It goes in a general fund that pays lots of different things. "
This is not really true statement even though technically this can be a misleading incomplete statement. This is not the correct way to state the true and complete truth. It is like fake/spin news.
Public General funds are not like anonymous donation boxes where the names of donors and donations are unknown. After donations are dropped in donation boxes, it is impossible to know who donated how much.
In case of Public General funds, every penny that comes in and goes out has a name, description and reference to Congressional acts and appropriations.
All the moneys that go into general funds and spent are required to be under congressional acts and appropriated by congress.
The point we are missing here is, we are talking about funds that were generated unlawfully like in Conservatorship NWS, and spent without congressional acts and appropriations. It is not et all difficult to identify these line items.