Final walkthrough, and "vacant" language on short sale contract

[Bienes Raices]

I've made offers on several short sales in the past but never actually bought one.

I've been told to put language in the contract to the effect of "property will be delivered vacant and all of owner/occupants' or tenants belonging will be removed before closing date".

What about the final walkthrough? Is this normally done on short sales? Does it need to be specifically written into the contract? And would you do it a couple of hours before closing, or a few days before in order to get back to the bank if there is an issue?