The finish decides what is possible
Washable low-sheen and semi-gloss paints tolerate spot cleaning and, with care, a light wash. Flat and matt finishes do not: rubbing a mark burnishes the surface into a shinier patch, and repeated attempts create a visible halo that is more noticeable than the original mark. Some ceiling paints and older water-based finishes will simply lift when wetted, taking the colour with them.
This is why the scope should record the finish rather than the room. A meeting room and a corridor might have the same paint or completely different ones, and the same instruction produces a good result in one and damage in the other. A short note at the walkthrough about which finishes are present is enough to prevent that entirely. It costs nothing at the walkthrough and prevents a permanent mark on a surface that was otherwise fine.
