The walls had to be washed down along with the cabinets but that was a few months after treatment to knock the bugs down to at least a level where you could enter the place (not habitable yet).If you watched Orkin and Undercover Boss this week on TV that was child's play compared to what I saw.

Also make sure your workers are washing out their grout sponges in the sink.  

I bought an apartment that had the Urine smell issues, pulled all the carpets poured buckets of bleach on sub floors and washed walls with it too, opened window's, let air out and dry for days.

In addition removing that wall would free up space for an island and allow a second kitchen sink where the old laundry wash tub was. 

As long as the tenant don’t wash down their grease everyday ( no guarantees) and you pump and inspect every 4/5 years my opinion is I like them.

@Adam Craig IMO, if the siding is in good shape, just pressure wash and keep it white.

But my grandfather had moved to the US from England, where people of his generation and social class were renters, that's just the way it was. He

Prime all exposed wood surfaces and apply two coats of paint on all previously painted surfaces $ 2,850.003A (I would only spend $500 on sealing windows, a little touch up paint, and pressure wash the exterior).

I have refinanced many properties taking the cash out to be used and so long as your new investment is available to pay the additional debt it's pretty much a wash.

It would be a full service tunnel wash with vacume stations, vending, etc.