VP Scavenger Kit
https://www.summitracing.com/parts/vpe-11189/overview/
I include this one largely for conversation sake. I'm not considering it but it is an interesting idea, if it actually works. Then again if it did work would there not be the potential to coat your cats in an oily mess? Clearly you could put it further downstream but the further away the less change it would actually scavenge anything and produce any vacuum whatsoever.
This is me thinking aloud anyways.