jcfay: the best method I have found (from FSMM) is the sludge wash method. There is an article somewhere with the complete details - hopefully somebody here can provide a link.
Make a "sludge wash" using 2 parts acrylic paint, 5 parts water, and 3 parts dishwashing liquid. Make sure this cocktail is stirred, not shaken or you'll have a lot of bubbles. Coat the area to be sludged with a gloss coat (future would work) and let dry completely. Then slap on the sludge in the corners and so on, and let dry only 20 - 25 minutes. Then using clean, dry cotton swabs, remove the sludge in the areas you don't want it (the high areas). Works great for me.
Rich