New Zealand is much more hostile towards foreign sex workers than for example Australia. Basically, unless you at least have residency, if you work they will find you and deport you. They are very active in doing this, so you cannot advertise anywhere undetected for long. Even for foreign residents in NZ if you are suspected of being involved in management - they don't have to prove it conclusively - your residency will be cancelled. In practice only NZ citzens are allowed to participate.