Translation:The tired man gets off the horse and goes into the restroom.
Does it really matter what the place is, if it is called a bathroom he can do what he wants to do once he goes in there. Maybe he washes his hands, sits in a chair, does his laundry. All it says is he goes into that place. If it's not a toilet he would not make use of it as such. There will be a sink of some kind. He could splash water on his face to feel fresher. Was it a laundry room?
Mosdó can refer to a room in which there is washing-up stuff and toiletries, or it can refer specifically to a sink.
WC or vécé can refer to the room with the toilet in it, or to the toilet fixture itself.
This discussion always gets more confusing because depending on where you are in the English-speaking world, "toilet" may refer to the room or may refer only the actual item.
(I think that's all correct!)