I wonder if a simple inline airflow meter would be enough to test flow in the OCC lines. That could test for flow before and after the CC to see if there is a flow restriction. Then possibly just use a simple vacuum gauge with a T fitting inline with the OCC to test for loss of vacuum before and after the OCC. With a long enough vacuum line on the gauge you could even read pressure in the PCV system under load while driving. This could actually get some test results on the forum about these OCC's and it would no longer be speculation but hard facts.
This is what I'm envisioning, but this one from amazon I think would not be able to measure enough flow it looks pretty small. .7-7.5 cfm seems like not enough.
Inline air flow meter
http://www.amazon.com/General-Purpos...879065&sr=8-10