Unless you like textured walls, don't paint over dust. Wash the walls with trisodium phosphate (TSP) or a mild cleaner, like Jasco's TSP No-Rinse Substitute. For smoke-stained walls, Toto uses a 50/50 solution of bleach and water. To clean a wall, use two buckets. Load up your rag or sponge from your cleaning-solution bucket, and scrub. Before redipping, rinse the sponge in a second bucket filled with clean water.
In England, little is known of the trade and its structures before the late 13th century, at which paint guilds began to form, amongst them the Painters Company and the Stainers Company. These two guilds eventually merged with the consent of the Lord Mayor of the City of London in 1502, forming the Worshipful Company of Painter-Stainers. The guild standardised the craft and acted as a protector of the trade secrets. In 1599, the guild asked Parliament for protection, which was eventually granted in a bill of 1606, which granted the trade protection from outside competition such as plasterers.