About the only thing you can try would be to soak the effected area in Ammonia. Ammonia can break down dried latex but I doubt it will completely remove it as the cotton fibers will have soaked up the pigment.
Soak the area. Let it dry out again, Get a Suede brush or a fine bass < not steel> wire brush the comb out the area, brush it in the direction of the Nap. This is going to pull out as much as possible of the broken down paint. After this process you are of course going to need to re-flameproof the soft good. I'm asumming, of course, that these are Commando, Duvetyne or velevet. If it is a more "flat" soft good you're pretty much hosed. Hit it with some flat black and only use it in the upstage areas.