Yah, they'd get action all right: The only kind of oil available that retained its viscosity at altitude was castor oil, and radial engines particularly threw it off in a continuous fine spray, such that by the end of a patrol the hapless pilot had inadvertently ingested a good teacupful of this natural laxative.
“The oil is known for its purgative qualities. It would be impossible to expose oneself to such an atmosphere and not experience certain difficulties.”
Ayup. This was never mentioned by the recruiters.