It’s difficult if not impossible to completely eradicate roaches from these rentals with 100% effectiveness.

Well, last I studied, measles, was essentially eradicated from the planet, via a little thing called A VACCINE... ...that is, until some really smart people decided to not provide the vaccine to their young children -which you know, worked really well, causing measles outbreaks, amongst those clever ones, to the extent we've not seen in 50 years.  

Of those 40 days they have a 10 day appeal period (that's the main delay) which some local lawmakers are trying to eradicate. 

They, too, said there is no way to eradicate them or completely seal the unit off because they only need 1mm to get through and can come right through outlets, vents, etc. 

I was able to eradicate the problem in about a week.

Usually when they're in the house they're also in the yard and can get tracked back in when people are going in and out....it's much harder to eradicate them from the yard when you live in an area that doesn't freeze.

I'd find a competent technician first.One other thing about insects - if you don't effectively treat the life cycle, you can't eradicate the problem.

The smell of cigarette smoke can be hard to eradicate after your tenants leave.

Taking steps to eradicate or extricate bats.

In my novice opinion, this is what needs to be done to the house:Mold inspection/eradication (water damage from leaking water heater in attic)HVAC neglect (possible mold)10 Fogged Windows (house has numerous large beautiful windows that have become opaque due to moisture)Pressure wash exteriorReplace Carpets (approximately 1500-2000 sq ft)Paint interior walls/sand and paint trimPlumbing hardware has all been removed/needs to be replacedPool filled with excessive amounts of leaves/debris (pump is running)Excessive amounts of trash throughout house yard and pool houseLive Oak growing onto roof (arborist needed)New Sod (currently all weeds)Pool Deck ResurfacingGarage Door Openers have been removedLarge golf ball sized chip on bottom of granite on islandresurface built-insExterminatorPatch holes/cracks in walls (about 10 fist sized holes)Many light fixtures missing (10 or so in closets and bathrooms)smoke alarms missingSo, part of me was disgusted and felt very guilty watching my buddy conduct a walk through via the internet.