Potassium bromide (KBr) added as a 'final' before coating, is the most common recommendation to reduce fog. A few mls of 10% solution is usually enough. Best, though, is to try to stop fog from coming in at all. Fog usually happens as a result of reaching for increased speed. High heat and prolonged ripening can up the chances, particularly in recipes with ammonia. Over-washing the noodles, or washing with distilled water can be a cause. Too much sulfur in the sensitizer, usually as plain hypo, is a common cause of fog. Unless you are using inert gelatin, you can't be sure you're not compounding the total amount of sulfur in your recipe.

Pierre Glafkides in 'Photographic Chemistry, Vol One', 1958, mentions benzotriazole has an addition to emulsions, usually as a final, but sometimes as a replacement for a small amount of the bromide before digestion (p.380). The amount of antifoggants can range anywhere from 20mg to 300mg per liter of emulsion, determined by trial and observation.

Happy Cooking!