This would be a bad move.  You have to stick to your pre-polygraph answers come hell or high water.

I see.  I was asking because in this video from the February 2021 Washington DC Spy Museum Polygraph Discussion, the NSA polygrapher Thomas Mauriello said that a guy, during his polygraph session, confessed to cheating on his wife 30 years ago.  The guy even went home and told his wife of his past affair that night.  However it wasn't a crime and the guy passed his polygraph.   

https://www.youtube.com/watch?v=QA9oA5gkd_w&t=1385s ; (starts around 23 minute mark, and goes on until about 27 minute mark).

This is a Very Bad Idea and we advise against it in The Lie Behind the Lie Detector. Make no admissions.

I think most of us on this board will agree that a polygraph exam is like a police interrogation; the polygraphers want confessions, or disqualifying admissions.  Without a confession, your polygraph charts are subject to interpretation.  Has anyone ever tried to use the strategy of giving the polygrapher a confession that will not disqualify you?  For example, say the polygrapher says you are having trouble on the question "have you ever committed a serious crime?"  So you fake a breakdown and say that when you were a young naive 18-year old boy, your girlfriend was 17 and you had consensual sex and feel you broke the law because she was under 18.  Or confess that you have been lying to your family members for years by saying you like their cooking.  Or confess to taking prescription medication that was for someone else, though it was 11+ years ago (outside of the 10-year scope).  Maybe admit that you ran over a dog 11+ years ago, told the police, tried to find the owner, but were unsuccessful and since you love animals so much you were distraught.  But you really have to sell these confessions.  Like break down crying and say you feel so bad because you have been hiding these things for your whole life and are scared you will fail the poly and not get the job due to these deep dark secrets.  Then the polygrapher gets a confession and may ease up on the interrogation.  Your confession is not disqualifying, you end the interrogation, justify your spiked charts, and pass.  Will it work?