If one spouse cheats does it help if the other then cheats in response?

brought to mind by a prior question.

Does it ever bring things back to, not the way things were but, a point where both partners can now move on?

Do both partners have to be aware of it for it to be effective?

If you know he/she cheated and it was a one time thing would you then cheating make you feel better? Vindicated? Satisfied? More able to continue the relationship? Less able?