this works well, but you need to clean the tsp off the wall when you are
done with a final warm water only wash, or it 'may' cause problems with the
primer or paint.

randy


I will add that cleaning the walls with TSP, before the painter comes
would
be my choice. Plenty of ventilation and warmth depending on where you
live.
Walls need to dry out.

tsp = tri sodium phosphate

wear rubber gloves with this mixture