Belkar: (speaking about Roy disguising himself as a woman) That's OK. I can always keep the memory of her for when I'm... alone.

Roy: Excuse me, I need to soak my brain in acid now. Maybe my ears, too.
Okay, uh I-I, saw some things, um I'm not the same person I used to be and I washed my hands in the hottest water I ever washed them in. And it really hurt. But the good news is it looks like I can pick up some over the counter medicine at the pharmacy. Does... Does anyone want to trade eyes with me?
—Bob Belcher, Bob's Burgers
Think happy thoughts. Little cute bees. Little babies. Tiny, tiny bunnies.
Jake, after seeing the Magic Man turn a bird inside out, Adventure Time
I've many a time tried to the impossible task of washing away the memory of a sight that should never been seen. And let me tell you this: Febreeze in the eyes only brings more pain.
Red Mage, 8-Bit Theater
Right now I would settle for the ability to stab out my mind's eye.
Black Mage, 8-Bit Theater
I think my brain just vomited into my skull.
—From a comics review of Identity Crisis

Thor: It is uncertain, Thialfi, from whence Sturm and Drang truly came. It is said by some that the great slavering bitch known as the Fenris Wolf was in heat, and lay with Surtur the fire demon, and that Sturm and Drang are the result of that union.

Baldur:On second thought, I will have an ale. Hope is to obliterate the mental picture our lord Thor has just placed in my mind.
Captain Marvel v. 4 #7
Great! Now I need to scribble visual clues after that onslaught. Thank's a lot, G'Pa! Remind me to wash my brain with bleach later would you!
Monica, Wapsi Square
Is there any way you can psychologically unsee something?
Tony DiNozoo, NCIS
Some things, once you see them, you can't unsee.
Richard Langford, CSI

Adrian: This is horrible, it's horrible! What are you drinking?
Natalie: Tea.
Adrian: Is it hot?
Natalie: Yes.
Adrian:Good. Pour it into my eyes!
Natalie: Mr. Monk-
Adrian: Do it! Blind me!

Monk

Diabetus: ...sorry, I had to remove my headset and pour bleach into my ears after that.
Slowbeef: Oh my lord, you got any left?!
Diabetus: No, I'm sorry, I had to use two hundred bottles.

<emufreak> I HATE CHANNEL TOPICS
<emufreak> WHY MUST THEY EXIST
<emufreak> AND WHY DO I STILL CLICK THEM WHEN THEY END IN .JPG

You watched it... you can't UN-watch it!
NarratorFuturama

Flashback-Dr Girlfriend: I can't believe you still have [my old outfit]. What are these hard chunks?
Flashback-Phantom Limb: My - tears.
The Monarch: TEARS!? YOU HAVE TO BE KIDDING ME! You know that sick deformed slob... you know he was pounding his invisible meat all ov-
Dr. Venture: That's it! Objection! Your Honor, I have children listening to this potty talk!
Judge: Sustained. I want that last bit stricken from the record. And my mind.

I don't care that trepanning is no longer a recognized medical procedure. I need you to drill a hole in my skull and pour in this bleach.
Cassandra CainCass Toons
It was at that point that I took a spoon and shoved it up my ass. Because if I was going to be in that much pain, I was going to do it to myself.

Tomas Kaberle: Hey everyone, guess who just waived the no-pants policy?
Jarome Iginla: Oh god, I'll never be able to erase that from my memory!

There are some things that you see, and you can't unsee them. Know what I mean?
Max California8mm

Dodoria And that's why I was considered the most beautiful - and fertile - woman on my home planet. Well, until Freeza blew it up.
Vegeta: He tends to do that. Also, eeeeeeeeuuuuuugh. (shudders)

I CLOSE MY EYES AND STILL I SEE!!!
DornailRaven's Dojo
Y'know they make a magic potion to make you forget all about the Prequels. It's called Bleach.
Grace, can your antennae function as Brain Bleach?
Awww, now I'm scarred physically and mentally!
The images are in my head and they are never, ever going away!
Bethany, Dragon Age II

Ben: Dad, if I never see another underground water pumping station or one more droch, I'll be happy.
Vestara: We still have plenty of cans of droch spray.
Ben: Yeah, but do we have any bottles of brain bleach?

Star Wars: Fate of the Jedi: Conviction, invoking this trope
(STOP PUTTING IMAGES IN MY HEAD THAT I CAN'T GET OUT LATER EXCEPT WITH A BULLET.)
Darren MacLennan, reviewing FATAL
My eyes, Servant. Cut them out immediately! It's too late to save them. The only thing I can do now is have them removed so that they never have to witness something like that again!
LouiseThe Hill of Swords

Might Guy: That's right, Lee! Shake your goods!
Gaara: ...Wow. I think I'm gonna need some mind soap.

Uuhhh! I need new eyes and a new brain!
Katerina DonlanGunnerkrigg Court
Pardon me. I've got to go poke out my mind's eye.
Frasier CraneFrasier, "The Ring Cycle"
DEAR GOD MY EYES! There has been many a sight that I wish I could have unseen, but none more than this!
Daken, on applebeans' "dancing fluttershy" post on Paheal[1]
I'm... I'm going to erase that image from my mind with a bottle of scotch.
Richard CastleCastle

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  1. (The Irony is that it hardly even counts as Rule 34)