But NOOOOO! Instead he can't resist barging in on Kirk in the chair, and giving him a full dose. There's no plan, he's just lost all perspective and impulse control. Perhaps he can't abide the "aberrant behavior" of people out of control, wandering the corridors and breaking into rooms in HIS facility. Perhaps he's really excited by the chance to show off his toy's capabilities on a strong-minded starship captain. Whatever his motive, it's all downhill from there.
We could argue that neither Lethe nor van Gelder are good examples of what Adams intends to achieve with the chair - or what he is capable of achieving on a good day.
Lethe might be an early experiment, and for that reason rather lethargic. And Adams more or less tried to murder van Gelder, as there was nobody there to stop him or catch him in the act. Kirk would need to be treated with finesse, as his return to the starship as a zombie or a raving lunatic would not work well, and yet he had to return somehow. But what if Adams indeed were to convince Kirk that everything is fine, by using the Neutralizer at high power but with expertise?
We never learn that Adams could not
have turned Kirk into a loyalist who would nevertheless be fit to return to duty as a starship captain. Despite the high setting, he is neither blandly amnesiac nor raving at the end of the day, merely convinced that he is in love with Noel; a good prognosis considering Adams' likely plans.
Sure, Adams has a hammer and sees a lot of nails. But he could
nail Kirk, or at least would be entitled to thinking that he could. He need not be cacklingly irrational, but merely suffering from some tunnel vision.