As a full time home inspector I have come across quite a number of less then desirable situations as I inspect house after house. No home is perfect, none I have inspected yet anyways. But I would much prefer that they at least be half way sanitary.
It was quite rare a few years ago that I would come across an exceptionally dirty home. I would inspect occasionally a home that was cluttered and just plain too small for all the stuff that the current home owner had. Now with the increase in bank owner properties unfortunately the frequency of nasty is in on the rise. These homes are sometimes vandalized by the previous owners as they are about to be forced out of the home. The previous owner may damage walls and doors. Sometimes they just remove them and take the doors with them as they relocate. Light fixtures and ceiling fans seem to be a favorite item to take. Not sure where they take them, perhaps they are selling them to help raise money for the next place to live.
One other reason that vacant homes can be not pleasant to inspect is that sometimes these homes become hangouts for teenagers and drug users. I was at a bank owned home once in where I found a couple of home made crack pipes and a needle laying next to a spoon. The home had no counters in the kitchen to lay down my computer so I used a shelf in the garage to place my equipment. The home was filthy and smell horrible. Mold was in several areas. The first thing I did there was to open the windows to get fresh air in there. All during the inspection I kept locking exterior doors and keeping an eye out for anyone who might wander in. I tried my best to touch as little as possible and I used antibacterial hand sanitizer frequently.
The carpet in the home was ruined. There were burn marks on carpet and chunks of the vinyl flooring in the kitchen was missing. Stains and filth were throughout the home. I was careful where I walked, This home was on a slab foundation so fortunately for me that there was no basement or crawl space to enter.
When people are looking to hire a home inspector to check out a bank owned home they should keep in mind that the home may have health and safety hazards to be dealt with. Buyers of these homes should not expect that because the home may be low in price or without some kitchen appliances that the home inspection fee should be reduced. These homes often take longer to write up the report because of the number of issues found. Consider that the fee includes hazard pay.