Cleaning acrylic emulsion paintings is challenging because of the material properties of the paint films, including their solubility. The goal of this work was to learn more about the effect of aqueous treatments on acrylic paints. Paint manufacturers were asked for their recommendations for cleaning these paintings and conservators were asked to comment on the damage observed in them and on the treatments applied. Responses showed that aqueous cleaning treatments are used, despite the associated risks, and that more technical information is needed about the effects of cleaning. The experimental section of this paper evaluated the changes in physical and mechanical properties of aged cobalt blue paint as a result of exposure to aqueous cleaning solutions. The results indicated that short immersions in these solutions caused a drop in most mechanical properties, but longer immersions did not; the drop after the short immersions was mostly due to the great increase in dimensional thickness of the paint films. Longer conservation treatment times are not being advocated.