How would ERP work for False Memory OCD? Should I allow the memory to play out in my mind again and again?

If you’re experiencing the memory as an intrusive thought, response prevention would include allowing the thought to be there and not engaging with it. Work on accepting your uncertainty about the memory and move on with whatever you need/want to do instead of doing compulsions. If you have any other compulsions related to the memory (like checking to see if people involved are OK), replace those compulsions with acceptance of uncertainty, too. Exposures could include writing and rereading a script about the memory, reading articles about similar situations, going to the place where the memory happened - whatever triggers your anxiety/distress and urge to do compulsions - without doing any compulsions during or after. I hope that’s clear and helpful. Good luck!

The E (exposure) is only half of ERP… the other half is response prevention. So the point of triggering the thought and experiencing the anxiety spike is giving yourself the opportunity to practice not-responding with a compulsion. So just looping through the cycle over and over isn’t the point… the idea is to break the trigger-emotion-thought-reaction cycle into its components and work with each part.

Yes. But don't try to neutralize the fear. Play it once. Sit with it, don't do anything, wait until it gets a tiny bit better and repeat. Over and over. Until it gets easier