I had a similar effect and still have it every time I perform an FMT at home, the next day my skin looks much brighter and I don't know why, there must be some underlying mechanism related to microbes we don't know about that affect blood circulation and skin collagen. I only notice this with certain donors and not with others.
That's interesting, the aerosol FMT thing. Can you link to any studies? There is a case I know personally of someone recovering from post-covid smell loss by simply smelling stool from a very healthy donor. I assumed this person probably ingested the stool rather than just smelling it, but never thought about FMT aerosol concept.