> And if a sales person invites a client to a strip club, they would do so understanding that it's a questionable thing to do,
Don't presume the sales person is inviting the client.
I do consulting now, and periodically have to go to client sites for presentations and training sessions. There's almost always a big client dinner one of the days we're there. Where we go out to eat, and what we do afterward, is usually driven by client suggestions. In my case, the "after dinner" activities almost always entailed some form of bar hopping, and has never included strip clubs. But that doesn't mean it wouldn't include strip clubs if that's what the client wanted, just that the specific clients I've serviced haven't ever had that particular inclination.
Note that I've only ever been the most senior person present from my company once, and therefore responsible for expensing the client-servicing night. The only direction I was given that time was to keep the client happy and to not blow past the budget for that trip (which had about $5k worth of cushion, after anticipated employee travel expenses). Most of the expenses are passed through to the client however (which is what dictates the budget), and some client agreements do have very strict stipulations on allowable pass-through expenses.