I personally buy into the "residue" argument much, but some new records have paper dust from the sleeve and then, as any, I clean it. If there is truth to the residue issue, which could be I'll admit, I think then you need a clean machine, not just a brush and fluid.

Mould release compound is an integral and absolutely necessary part of the process of pressing vinyl LP's. Some companies go to the trouble of removing it, not always as thoroughly as they should. Others don't bother. The problem with mould release compound is that it collects dust and other contaminants and forms a nasty layer over the entire LP that sometimes gets glued to your stylus tip. And yes, a vacuum LP cleaning machine using a liquid cleaning fluid is the only fully effective way of removing it.
Welcome the the obsessive world of the LP.