This was posted an a fb group, but it’s very interesting if you use air dry! How Much Water Can You Safely Add to Acrylic Paint? | Just Paint
Yes but keep in mind these findings are based on painting on canvas or paper. You cannot thin the paints past a certain point and have them stick well to vinyl or remain stable over time. They will fade if thinned too much.
I found it interesting that they pushed the limits so far! 1/100 ratio? Crazy!