As a condo owner I have seen just about anything plus everything when cleaning out arenas once a renter has vacated.
I have had to substitute flooring disfigurementd by pets, redone plumbing that was jammed or disfigurementd by irresponsible people, plus even had to pay for industrial cleaning in some cases, and this last issue almost had me giving up on they whole process entirely.
Sure, I was able to keep the security deposit, but, that didn’t come close to covering the cost involved in repairing the Heating, Ventilation plus A/C system. Not only did I have to have the air duct cleaned due to the stash of drugs my friend and I found tucked in the vents, I had to have the component repaired because they had kept it running non stop with a humidifier set up to help grow the plants in the basement. They had plugged off multiple of the air vents with cardboard so that the heat could be directed to the growing section more easily. This had causes a build up of debris at the opening of the vents that can only be described as gross. I had to make sure that the Heating, Ventilation plus A/C system was scrub plus safe before I could rent the component to anyone else. I have changed my rental agreement to include annnual inspections because I want to ensure that renters are not damaging my proberty like that again in the future. I guess it solves the mystery as to why the previous people never complained about anything or asked me to service anything. They didn’t want me to see what was honestly going on in the apartment. I won’t make that mistake again.