Here is a simple device you can build to dry and steam ripen your rust blueing project. It s a simple cardboard moving wardrobe with a a flap door cut in the bottom. This allows the introduction of a mild steam source or heater. It will greatly reduce rust times and produce superior work. Simply use a box cutter to open about a 10″x10″ door at the bottom. Use steel wire to hang parts from the cross-bar. Insert a clothes steamer, vaporizer, or other  low steam source into the door. Make sure it cannot ignite the cardboard! Steam for about 30 minutes or until you get a good ripe rust. I use a small handheld clothes steamer. Prior to boiling or steaming in the steam pipe, heat the ripened steel in the box with a small space heater like that pictured below. This will prevent spotting.

Moving Wardrobe