Straightwire innocent (non-painful) moments.
Problem: The preclear cannot remember a bad moment he had with someone.
Action: Straightwire or scan good moments with this person until the bad moment shows up.
Problem (in detail): The preclear cannot remember a bad telephone conversation with a certain person.
Action: Straightwire or scan any and all telephones, then telephones ringing, then phone conversations with anyone, then any conversation with the person in question. Then contact the bad telephone conversation.
If it is still occluded, repeat the process.