Strangely, I’ve already heard of this. They have special oxygen saturated fluids that can be pumped up the butt for much better oxygen absorption.

They’ve also even successfully tested ‘drowning’ rats in the stuff, and apparently animals can even literally breathe the fluid and absorb the oxygen with their lungs, but they say it’s a strain for the lung muscles and also high risk of pneumonia once the animal is removed from the fluid and trying to go back to breathing air normally again.