They don't stain, never need to be sealed, don't chip/crack as easily as granite, and if you pick them well no one can tell the difference from real stone.

To cover up any smell, you'll likely have to not only wipe the walls and baseboards but repaint the entire house to seal in what smell is left.  

That stuff will seal in just about anything.  

The file was sealed so the eviction never shows up in public records.

@Bret Weigel - here in North Texas, we have some great programs that provide FREE blown-in insulation, as well as weather-stripping, sealing windows and other energy-efficiency improvements. 

If that's the case, the real problem was that the sink & faucet weren't sealed properly to the countertop.

@John FiastroGo with the hardwoods it will reduce your ongoing costs.We do a light buff and then put several poly coats to seal the floors against liquids (beer, urine, juice etc.)Another great product is vinyl allure flooring.

I think I'll try cleaning it once more with one of the items suggested at the link Jay provided and then seal the driveway with a topcoat.

If you wanted to be extra safe, you could also try mailing it to the address they just vacated and hope that they have their mail forwarded to their correct address.But at this point, I would just do exactly what @Dawn Anastasi suggested and keep the returned envelope still sealed with the check inside, along with the email documentation of your attempts to contact them, and let it go until they contact you.  

Somehow it malfunctioned, which I also agree shouldn't have been able to happen if it was bolted and sealed properly.