Some localities have gross rent floors that you have to hit before requiring an occupational license. 

See if they can run the cutter through there and clean it out.

You might be better with an experienced co-host and Airbnb expert and a handyman with cleaning crew.

It will take a huge amount of work to upgrade the property which has not been properly maintained, so we'll be doing a lot of infrastructure rehab including adding HVAC/AC, upgrading the wiring, and bringing the old floors back to life.

Plan is to wall it off and convert to a 4br/2ba,  update existing bath and kitchen, new floors,  interior and exterior  paint.

A rental just needs to be clean and servicable.

The only times that I've allowed this was a situation where there was a cleaning or a maintenance issue, which ultimately falls on me.  

Tell her to empty and clean it, and you'll let her out of the lease immediately.

Not only does this pertain to structural wood but also to wood flooring.

When the 5 year treasury fell too far, the bank doing this told me they were at the floor.