I'm more/less with Dave. Except any blow by past the rings will get in the oil regardless.
I've seen a couple of planes that have the vent tube strapped to the exhaust, metal tube of course. Any oil mist basically gets burned to a crisp. An issue is if this vent gets plugged (like frost). Most have a 'whistle' tube or small slit in the rubber tube way upstream just in case. Don't want to be blowing a crank seal out!
Rick