It should be possible. Try a scrap model first. Make sure the acrylic coating is totally cured (allow one day) before appliying your wash. I've had problems using acrylics, then applying overall finish with enamels and trying to clean any dirt with acrylics thinner, I don't know why but i goes through the enamel and attacks the acrylics beneath.
Have you tried the sludge wash with acrylics? I find it a lot easier than using enamels and it doesn't involve any thinner at all: mix five parts of water, two parts of acrylic paint and three parts of liquid soap, make sure the coating where you are going to apply this is glossy (and perfectly cured). Apply the wash with a soft brush on the desired areas. Allow to dry a few minutes and remove any excess with a cotton swab, then seal the wash with an overall finish.
Hope this helps