GRAVITAS: Dude, that is seriouly in poor taste. Ever visited a concentration camp? Met someone who was imprisoned there? I can't even joke about that stuff since I saw Dakow.
Now.... Legalize the Trade and Build a Red Light District:
They honestly SHOULD do that. Now, Amsterdam is NOT a good model...nor is Germany. They were forward thinking for their time and I guess appropriate for their location... but those models are not suitable for Vancouver.
If a red light district is created in Vancouver, it should be government run facilities and anything but gaudy. It should be low profile, clean and professional.
Also, various services should be made available to the women working in it...ie.... the current street walkers. Everything ranging from detox to re education. The aim of any red light district here should be to get the women out of the trade WITHOUT shaming them or pressuring them in any way.
What about the others? I am of the mind there should be several classifications of liscenses set about... MP, Private and of course, general worker in a designated RL district.
With everything made legal, it would be easier to tax and fine as is required to maintain a safe and healthy environment for the workers. Also, worker health would require monitoring.
Also, parlours would have to have more private displays... places like Mdm Cleos would be considered gaudy and would be deemed to be bringing down the percieved quality of the neighborhood. There is no need to appear as anything else other than any other business.
Even sex shops should really have a more conservative front to preserve location values.
Mind you, I'm a fairly conservative fella

But in the case of legalizing the trade, I think for the sake of the workers it really should be done. You can't stop it... governments have tried to stamp it out ever since they came into being, yet none have succeeded. It's time to look after those that need the help and show a bit of compassion for those in need, don't you think?