Can't imagine that it matters unless it was a messy crime scene or something.  

I doubt they will "help" you, and more likely could sabotage your efforts by leaving it messy or making a scene.My gut feel is to get them out of there before showing it.  

Are the desks and offices messy or clean?  

Add your hourly for the time and work just doing your paper work, screening, orientation, lease, and then, you may even find she leaves it messy enough that you have to clean up some again...

When things got messy with a tenant a few years ago, Person A fronted lawyers fees to evict the tenant and handled court appearances.  

I totally agree that steps should be taken to balance back the market on rents, as cities do need lower income workers to have safe, affordable housing, but in many cases, that should be accomplished by policies that encourage more housing to be built, not by a messy programmatic attempt to cap rents.

I had one prerty that was in a huge mess. I

It reduces the volume of materials , but it is a bit more messy .If it were me I would rent an excavator and hire a dumpster company , you can demo and haul away a house in 2 or 3 days with equipment .

Otherwise it can get a little messy.

No real damage, just messy.