The problem, of course, is the nature of this lie.  To be found truthful, one would want to demonstrate physiological reactions.  Thus, countermeasures might be highly effective.

That, and there are some things most people (in this case, husbands, boyfriends, etc.) really don't want to know the truth about.  If the lie is good enough that one would need a polygraph to tell the difference, then it's probably good enough for most purposes ;)

Skeptic