Stick with your job and hire all that out.Really --and I know this isn't where you were going with this -- you have to figure out WHY you're doing this, as @Steve Vaughan gently keeps trying to point out in his posts.

Your FIL probably hadn't jumped into overalls and crawled underneath the house - any contractor that does and who has your interests in mind would be able to point out first signs of termites, mold, moisture and things like obvious cracks in foundation that old houses are famous for.

It probably has a 1/4" screw you need to remove, pull it out and gently clean with sandpaper.

I have also applied it to the shower stall ceilings to avoid moisture issues & paint peeling.

I am NOT aware of anybody who has died from exposure to this mold.WHY MOLDS KILLMolds grow in response to moisture.  

If you’re finishing a basement, you’ll have to pay major attention to any issues with moisture.

Even then, it won't be totally flat, but gently sloping is possible.Homes under 200k are really in demand.

Expansive soil problems are driven by changes in soil moisture, the soil will expand and contract during wet cycles.

If the smell is purely due to moisture, Home Depot sells DampRid in various scents.

And yes tenants may not be as gentle as I'd like and I understand things can when there are kids living in the house.