You seem to be suggesting there would be logistical problems with the idea of the prostitute/receptionist, but I think that even if those problems were solved it would still be a bad idea. If there was a clause in the contract that sex had to be outside the workplace and the money to pay for the sex act had to come from the entertainment accounts and the company had no problem attracting female employees or retaining workers, would you support it then? That would seem to answer all your logistical concerns.
I think the only way to solve them, pay all employees way above market. If you do that, it doesn't matter the money to pay the receptionist comes from entertainment accounts.
Another hard to solve issue is envy. A manager in the company might want to have their own receptionist.
> would you support it then?
In a hypothetical world where all parties are totally OK with a boss sleeping with a receptionist - sure, why not?