I keep forgetting to update this post - the mystery smells was......the stove!

All great insights already here Winn, but if you are able to oversee the painting, there are some ways to help with this often unavoidable turn over expense....For example, this time insist on some high end paint (think specialty paint store or the very best big box stuff); try a pearl or washable finish; I like one color for all the interior of all my units, ideally a white that can hide some imperfections (know and keep the code); this means no color or matching mystery later; then on the next turn over, see if you can't get away with just a wall cleaning; use a damp sponge mop with tsp or a tsp substitute  (and then rinse it with a clean water and a damp sponge mop)..not too much water, just damp.. 

The cash flow in and out on these properties is a bit of a mystery to me so it's hard to determine if or how much I should leverage and if my other rentals would have to float all or some of the expenses until I get a big payday with a harvest. 

One of the reasons low C-class tenants are what they are is that they are almost always ignorant and terrified of the mysteries of alternating current.

If you held it for a month, and your holding deposit reflected a month's lost rent, for instance, that would be fair.But, to charge a month's rent as a "holding deposit," when you only held the property for a few days, probably wouldn't fly in court.There are no real mystery magical clauses you can put into leases that allow you do do anything that is not "reasonable."  

NO mystery there.

Maybe it keeps failing for some structural reason.I agree with the others that say that if you charge this tenant for a mystery problem like this, they'll simply hide it and not tell you about it or try to fix it themselves.Picture being the tenant knowing that the toilet is leaking again, and now they know that if they call you, it's going to cost them $200 they don't have.  

What I do, is try to look at the worst case scenario.And it's my opinion, that in the worst case scenario I can think of - where some tenant says their kid or dog got sick from eating soil on your property, I could argue in court that there would be no reasonable expectation for me to "assume" that the property was unsafe - given the fact that the city gave the okay, and I have the documentation to prove it.I would be quite happy with that risk.You can drive yourself crazy over this one, wondering if even if you test the surface soil and find nothing, that there may be some mystery leak buried down in the soil that may somehow rise to the surface, only to end up in the mouth of some dirt-eating child...  

So, there's no mystery to that risk here.  

I write a mystery series set around a dog kennel, and I'm a total research geek to boot--not to mention having learned a great deal from the BP forums!