"OK, let's say we sign a confidentiality agreement, however if either party ever produced it, and attempted to enforce it, well... your "confidentiality" is pretty much blown, right?"

      You would have no need to enforce it, unless the other party either threatened to breach or breached it. If the former, you would simply seek equitable relief to prevent the breach without disclosing in court the subject matter of the agreement, or obtaining a second confidentiality agreement limiting disclosure to the court.

       If the other party breached it, there is no way you could enforce it retroactively but you could recover damages and obtain specific performance to prevent future disclosures.

       Now I’m not sure what this lady is promising to keep “confidential” and from whom but you would also have to factor in the effect of illegality on the deal.

      Contracts that are illegal or against public policy are sometimes, but not always, unenforceable. Sometimes they are void; sometimes merely voidable. It is a complex area. But merely contracting, for example, “I will never tell your employer about our illegal relationship” probably would be enforcible; contracting “I will never tell the police” probably would not.