Out of the breather comes oil, oil mist, moisture, acids, and other garbage. Guess what goes back into your engine in addition to oil......
 
I built a separator a couple of years ago and I wanted to test the "contaminated" oil issue that keeps popping up. I collected the oil that came out of the separator and checked it for moisture, etc. Visually it looked perfect and I collected the oil for over 50 hours of flight. I would have absolutely no problems with returning that oil to the engine.
 
Or use the Andair system with the condensate trap.

We have it on ours - a bit like a poor man's Christen system.

5 hours only - 2 drops of water in the trap, no oil on the belly.

Not that I have been doing aeros in my fly off you understand - Oh, dang, it's on the video :D