When i'm stripping miniatures, I use Simple Green, but i'm submersing them and leaving them overnight. I wonder if you had a cotton ball soaked in it, and then resting on the area it would do the trick? it makes acrylic paint slightly rubbery, so you could in theory just peel off the offending splat. Simple Green is not as harsh as acetone, and smells way better too!
Of course the other option could be to get a scalpal blade and lighly drag it across the paint mark.