Exactly like variolation, except you do it intelligently to minimize lung infection.
SARS and SARS-Cov2 are both ACE2 dependent for cell entry.
ACE2 expression in AT2 cells in the lower respiratory track is known to be on the apical surface, that is the side of the cell facing airspace, not the basal surface facing vasculature. Hypothesis would be that lung infection is much more efficient and virulent by droplet delivery rather than by virus circulating in blood stream. I am also under the understanding that the kidney and heart complications are due to po...
I proposed in a another thread that variolation of the GI tract, where there are known cell populations expressing ACE2, might be preferred to lung. Avoiding the lung infection from the the apical surface of AT2 lung cells sounds like a good idea.
It's unclear to me that you wouldn't end up with a worse clinical course in this case - perhaps you wouldn't, but I'm not sure why you'd assume it's safer.