Influencing someone to take an action that you know she will regret afterwards is manipulative.

What if you also "manipulate" so that it will also not be regretted afterwards?

In marketing at least, there is the concept of customer retention through anticipating and countering buyers' remorse... which mostly, AFAICT, consists of providing a customer with arguments to use to explain to co-workers, friends, relatives, spouses, or whomever why their purchase decision was a good one. This strongly implies that at least in the purchasing arena, the main reason people come to have buyers' remorse (besides crappy products) is that the purchase makes them look bad in the eyes of others.

Hence the marketing adage that the primary function of facts and logic in a sales pitch is to provide the customer with a rationale that lets them prove to themselves and others that they made the right decision... but only after they've been convinced to make that decision based on emotion.

I believe there's some discussion in the PUA field of similar "buyer's remorse" issues and providing the same sort of supporting rationale, except that such rationales are more to allow those women who are uncomfortable with casual sex to rationalize that it e.g. "just happened" (i.e., neither she nor the PUA truly intended it, so she is neither a slut nor a victim) or that it falls into the category of "once-in-a-lifetime encounter", or something else that can be reconciled with her belief system or social image in a non-harmful way.

In either case, a wise "salesperson" takes care to find a way to allow a person to reconcile their actions with their self-perception of "character" or their "usual self".