I have been to "cottage country" where it is the unspoken law that you leave the place as found. So it if there is a laundry facility on premise it is expected to have the sheets and towels cleaned (if possible). However saying that, this has to be clearly stated in the description and/or house rules.
Most people travel so they dont have to do those kinds of 'chores'. So if you want to have the sheets as clean as you wish for your guests, then you have to clean them. I would NEVER trust a guest to clean to my standards. Wouldnt it be terrible to find that they had just removed them and folded them to pass off as clean???? It's bad enough that I have bleached all my new shirts to death trying to make sure the rooms are germ free, but would not want to chance dirty linens. My guests complain that the kitchen is not clean enough. Hello.....it is a commercial kitchen approved by the Board of Health and it is beyond clean with bleach! (it does clutter up easily when I return from a catering job...duhhhh)...and guests give me a 4star for cleanliness because of that. I would love to see how these people live.
BTW Never ever assume that your guests are bug free. I ended up with scabbies. It is very infectious. When I strip beds, I put all the sheeting into the middle of the bed sheets and fold into a ball before removing from top of mattress. Roll tight into a ball and place in a clear garbage bag to carry to the laundry room. I do the same for towels. Then I just dump into the L. Tub per load with as little handling as possible. Vacuum twice and dump the dust outside and dispose .