Oh, and by the way I should point out that the amount of oil pulled in through this method is very small, almost nil when the engine is healthy. IF you have a lot of blow-by then it is NOT a healthy engine and you will want to vent them to atmosphere to keep from pushing excess oil into the intake.
IMO that is the best way to tell the health of a turbo engine, check the blow-by at idle and look for signs/smells of oil burning.
When my engine went bad the first time I had it turbo'd when the pistons cracked...it had enough blowby to be sucking serious oil into the engine through the pcv and pushing oil out the valve covers back into the intake and turbo. There was oil puddled int the turbo and some in the intercooler. There was enough back pressure under hard boost to push the dipstick out of the tube a little bit and start spitting oil on the engine and hood.
