Sleeper Cell
In terms of being an actual doctor, Compass Carburettor knew shit about it, incapable of differentiating even the simplest of symptoms.
So, the gimmick was only of him treating physical injuries and mental illness.
After he cured the patient, Compass Carburettor didn't immediately wake him up, recovering his Origin Essence using Essence Stones first. He then focused on the patient's mind, leaving a mental cue there.
Origin Art—Sleeper Cell!
As the term implied, this ability planted a mental cue in the minds of the target, like a seed. And, when the necessary conditions were achieved, this seed would sprout, causing the target to perform certain actions.
Until then, they would be living their lives normally.
Though, what he made the targets execute wasn't anything serious.