Is your goal to reduce the oil-consumption to zero? Good luck
1L/20hrs is really not a bad stat. 1L/5hrs is the limit and from Turbomeca's side acceptable, specially if it is working hard.
We had a B3 suddenly using 0,5L an hour, and that turned out to be a partly clogged oil return line.
I don't think Rock Docktor turned the went line upside down, but changing the angle of the top of the went line i.e cutting it slightly. I have heard this been done, but for me the most important thing is to never overfill the reservoir. I always add oil just after shutdown as Victor Papa mentioned, and never more than half way between the bottom of the glas and the MIN line when parked flat.