Just wondering, are these very short lets, days, weeks, months?
Surely you insist on substantial deposit and have inspection before departure, no?
Used to be a Director at a Timeshare resort- with many units, most Saturday to Saturday, and a few Sunday to Sunday. We had many bad experiences of damage or theft- but due to weekly nature with 10am check-out- it would have been much much more expensive to hire enough staff to do check-out, than pay for repairs or replacements. 99% of exchangees were honest and decent.
I suppose I shouldn’t have been annoyed, but…

You never can tell, can you?