There is a difference between curing and drying. Curing is the chemical process that takes place when paint is exposed to air, drying is just the solvents in the paint evaporating. Latex cures at a very slow rate, even if temperatures are ideal and it dries quickly. Until paint is cured, it can be cleaned with the same solvents that keep it in a liquid form, once cured however, that is not the case.