Floors had to be removed and concrete vinegarized.

Then we wash all hard surfaces with vinegar.

I have heard a solution of 1/2 vinegar and 1/2 water works but i have never actually talked to anyone who has done it.

In my opinion, your manager needs to have the special sauce of piss, vinegar, and life-coach to make that area work, especially in the C-class stuff.  

I read online this recipe hahamix one teaspoon baking soda, one teaspoon vinegar, ½ teaspoon orange essential oil, and about 5 ounces of hydrogen peroxideGood luck with it!

You'll catch more flies with reasonable, thoughtful offers than you will with the vinegar of stupid, super-low-ball, random offers.

We also put cups of vinegar inside the cold air return duct so it would suck the vinegar thru the system.

Hint:  honey always works better than vinegar.

For one tenant that had a cat (inherited tenant and the only cat I've allowed), I had to soak slab with enzyme cleaner, didn't work well, then soaked in vinegar, replaced subfloor boards upstairs, replace trim all around flooring -- it's a huge undertaking requiring multiple applications.     

Look into cleaning with strong products or a vinegar and baking soda mix the windows and doors, specially the frame area where it might not be painted.