I would stay away from "bulb grease", that may be deemed as breaking the warranty, however removing the bulb, inspecting the contacts in the unit and on the lamp itself, wiping them clean from oil/grime with a lint free micro-fiber cloth [the sort you clean eyeglasses with] might be in order. Also when reinserting the bulb be sure to push it in firmly so it is seated as far down as it possibly can be.
Ask other household members to inspect the image and see if there might be some truth to this "some individuals are more sensitive than others" claim, which is sort of true about flicker in general.
I concur that with the AC off you obviously can eliminate that as a possible cause.
You also might experiment with trying to see if the problem goes away from disengage all extra processing. Turn off the auto iris, the frame interpolation modes, and go to "game mode" which gives the least processing to the image so there is little lag.
You have a normal screen, not a micro-perforation acoustically "transparent" screen, right?
In A/V reproduction accuracy, there IS no concept of "accounting for personal taste/preference". As art consumers we don't "pick" the level of bass, nor the tint/brightness of a scene's sky, any more than we pick the ending of a novel or Mona Lisa's type of smile. "High fidelity" means "high truthfulness", faithful to the original artist's intent: an unmodified, neutral, accurate copy of the original master, ideally being exact and with no discernable alterations, aka "transparency".