In my days of camping, long since over, we would bring biodegradable TP even for the outhouses we sometimes would find. When no such luxury accommodations were available, an area was designated, rope wrapped around a few trees, and told to watch for land mines.
We didn't do a whole lot of hiking as a family, but Dad would occasionally reblaze sections of the Appalachian Trail but the discussion of how he dealt with it never came up.