Quote: (Originally Posted by
mountain diver)

02 in the right lung simply for the purpose of an 02 flush, place the hose to
the left lung and you no longer have the ability to 02 flush.
all the best.
It is actually easier to O2 flush from the exhale side. Your lungs push the gas through instead of having to crimp off the inhale hose and let the pressure circulate it.