If uncertain about washability of paint, check on an inconspicuous place. Remove discoloration with non-abrasive household cleaner. TSP and 1 cups household bleach in 1 gallon water. Allow several days before painting of papering. Hotter water means those water molecules are moving around quickly and aggressively, and breaking down the dirt better and faster.
Heat helps remove grease or wax faster also.
Floors Hardwood Mop or vacuum and periodically use a paste wax. If excessively soiled, clean with mineral spirits or commercial floor cleaner, then wax. Linoleum, Asphalt, Vinyl, Vinyl-Asbestos and Rubber Sweep, mop, or vacuum. Clean with diluted detergent or recommended floor cleaner. Wax to protect.