Back in the 30’s my family lived on a farm in Jersey County, Illinois. Every bed had a chamber pot under it - the colloquial name for which was “Thunder Mug”, for obvious reasons.
My Grandfather had had a stroke, and was basically wheelchair ridden. Grandmother had a chair with a hole in the seat, and a little platform just beneath, where the Thunder Mug resided. Grandfather had to use this on a 24 hour basis, as the outhouse was some 50 yards away from the house, and inaccessible via wheelchair. Such was life in the olden times.
During WWI it was considered the height of humor to purchase a chamber pot with a picture of Kaiser Wilhelm on the bottom.
Forgot to mention - that bit about using the Sears catalog for sanitary purposes in the outhouse was absolutely correct. I got most of my information about partially clad women out of the underwear and girdle section of that publication.
Ours was nailed to the wall within easy reach of the occupant.
In some times, in some places (but by no means all) a wad of cloth or a seasponge might be found tied to a stick near the facilities. One would use this to clean the nethers. I know they’ve found such evidence at Roman public toilets - where presumably the rag was shared among users. (Ew.)
People who were wealthy enough to employ laundry staff in the middle ages used rags, which were cleaned and reused. Commoners used their hand, which they would then rinse in water, or during summer months, mullein or other soft leaves.
Nowadays, we make artificial fertilizers to boost yields and keep fields producing. Before that, you have to have some other way to get all those rich nutrients back into the agricultural system. If you’re constantly growing food and shipping it to cities for people to eat, you’ll want their waste back, or you’re going to rapidly deplete your fields.