We've stayed in many timeshare condos with excellent experiences. We just check the dishes and utensils as we pull them out for use. If they don't appear spotless or if the kitchen (cabinets, counters, utensil drawers, refrig) appears in any way dirty, then they go right into the dishwasher. However, we've rarely had any problem. Most timeshares ask guests to load up the dishwasher before leaving at the end of the stay and housekeeping puts everything away.
I know these dishwashers don't get as hot as restaurant dishwashers. But I would not hesitate to eat from the plates offered at a friend's or neighbor's home. So I think it's a non-issue unless there is something obvious dried-on that the dishwasher just couldn't clean. Fortunately, we've stayed in really lovely places and most have been very, very clean.