this difficulty inhibiting thoughts that i know are irrelevant has long been an issue for me. i had to build a "memory palace" style visualizing technique for "disposing" of thoughts that i know aren't relevant, but can't help fixate on.
i imagine writing the thought down in vim, then moving the file to a USB stick, then taking the usb stick into a zip-lock bag, putting that into a specific pocket of my backpack, getting on my bike, and riding from my apartment down 101 to the NASA base at AMES, throwing the backpack into a red bin which is loaded into a rocket and shot into space.
the visualization is so detailed and specific that it takes all my attention to render that internal movie; after having expressed the thought syntactically (i actually imagine writing the thing down in vim and moving my fingers accordingly), it gets moved from "the thing actively afflicting my consciousness now" to "a thing i was thinking about". often after the rocket takes off, i can remember i was thinking something that bothered me, but i can't remember what it was. my mind will sometimes grab after it, trying to remember - and if it surfaces i get agitated again - but i can usually stay focused enough to distract myself by going for a walk or establishing a small, easily obtainable goal to fire up the ol' task positive network again.
It's not quite as detailed as yours, but I use a "trick" of the same kind to chase those obsessive thoughts.
I see myself on top of a miles high cliff, standing next to a safe. I somehow extirpate the thought by breathing it out into the vault, which I then lock and push off the cliff.
I then have to wait and when I "hear" a distant noise, I can't remember the thought, even though my mind perversely tries to remember.
Anyway, I'm glad to see I'm not the only one having to resort to such tactics...
I sometimes use imagery of a toilet flushing and the thought going down, several flushes if necessary (imaginary water is free!) Also, imagining white noise (visual and auditory) washing out the thought, increasing in power until it wipes away the thought like waves on a beach erasing patterns traced in the sand and then fading out, seems to work well. (I suspect using (imaginary) noise might have some actual biophysical basis for why it works, but that's just speculation.)
i imagine writing the thought down in vim, then moving the file to a USB stick, then taking the usb stick into a zip-lock bag, putting that into a specific pocket of my backpack, getting on my bike, and riding from my apartment down 101 to the NASA base at AMES, throwing the backpack into a red bin which is loaded into a rocket and shot into space.
the visualization is so detailed and specific that it takes all my attention to render that internal movie; after having expressed the thought syntactically (i actually imagine writing the thing down in vim and moving my fingers accordingly), it gets moved from "the thing actively afflicting my consciousness now" to "a thing i was thinking about". often after the rocket takes off, i can remember i was thinking something that bothered me, but i can't remember what it was. my mind will sometimes grab after it, trying to remember - and if it surfaces i get agitated again - but i can usually stay focused enough to distract myself by going for a walk or establishing a small, easily obtainable goal to fire up the ol' task positive network again.