I am sad that you have not enjoyed your stay as much as you would have liked. However, I change the sheets and I put some clean before each visitor. As I wash them with bleach, halos can be created. Likewise, as mentioned in the ad, I have a dog. The hairs can cling to textiles despite brushing, but they remain clean and freshly washed.
Regarding sleeping in the sofa, I never prepare because the sofa can be used to watch TV or dinner if you arrive in the day. The sheets and pillows are ready to be used and put next to the bed.
I tidy and wash my apartment the same way before each visitor and you are the first to inform me about a concern about the sheets. Even if I do not understand how you could have found them unsuitable, I would pay particular attention to them in the future.