This is a prototype setup Ive recently put together.
The intake bolts do not have a hole on the shaft within the intake plate, so nothing can get into the intake, throttle body, intake manifold or combustion chambers.
The center port on the can is for pulling vacuum, and the vac supply comes from the unused nipple on top of the throttle body, which is behind the throttle plate, where any PCV vac source should be, vs in front of the plate on a Harley OE setup. Im using an air speed control valve, and have the vacuum adusted to 5 inches.
This can will catch the unburned fuel, water vapor and oil and other crud, and the extra vacuum will be helping to not only open the umbrellas earlier, it will also help evacuate the fumes and crud more, whilst also intruducing more crank case vacuum by the time the umbrellas slap shut again, which will aid ring seal and lower the blowby, among other things.
Im currently desiging different breather bolt setups so this can be used on just about any intake, and Ive since redesigned the coil pack mounting bracket to bring the can much closer to the coil.
So far, all Im getting is a bit of water, which means this is definitely improving ring seal and oil control, and reducing blowby bigtime, as usually, there would be oil, unburned fuel and the white, nasty slag that you get into the intake tract.

 

Interesting. I'm looking forward to read all the comments from people smarter than me!