On longer trips (next week when I leave, it'll be 4 weeks in South Africa), it becomes necessary to do laundry en-route. The concept of self-service laundromats seems to be rare (not nonexistent, but uncommon) in South Africa. Fortunately, we've found several guesthouses who have said that we are welcome to let the staff do our laundry "just for whatever you'd like to give them."

How much would an appropriate tip for an average-sized load (one week's worth of clothes) be? I have no clue if we've been massively over-tipping or under-tipping for that...