The idea of "you are what you think" is a key point in this theory and I can see the "Benjamin Franklin effect" being of help in two major areas for the WS.
The first example you give is a great example of the small steps a WS could take on rebuilding intimacy in the relationship with the BS by re-framing ones thought process. Especially for the WS who rewrote the marriage narrative in order to justify the affair or for those demonized their spouses, this positive reinforcement can go a long way to restore some needed balance.
The second example would help create indifference to the AP. Anything other than a very cool and professional interaction with the AP always runs the risk of possibility of reigniting the delusional romantic wayward thought process. Withholding any positive reinforcement would be of help in this regard.
The BF effect is often cited as an example within cognitive dissonance (CD)theory, which says that people change or create their attitudes or behavior to resolve tensions, or "dissonance", between their thoughts, attitudes, and actions. In order to resolve the dissonance between perception and reality, PMA (positive mental attitude) can be a major tool in the healing process. I once knew a fellow who used to constantly and continually recite the mantra of "Sonny is good, Sonny is great" to himself daily in order to positively influence his self-image.
BTW, while there is a rule that says it is a violation to post advertising or any form of commercial solicitation without the express written consent of SI, in practice, if you are linking to a non-commercial site that provides information in support of a member or of general interest to the SI community, then its a common practice and quite acceptable.
What lies behind us and what lies before us are tiny matters compared to what lies within us - Ralph Waldo Emerson