Question: If I've had a few wood fires in a metal firebox (Majestic), is it adequate to clean the firebox myself before installing ventless gas logs? Is there any particular method or cleaning solution to use? Does the fireplace and flu need to be professionaly cleaned? Thanks for your advice Answer: Sounds fine. If you've only used it a few times it should be OK. Use a solution of Baking Soda and water. The flue does not have to be cleaned unless there are large amounts of creosote which might fall down into the firebox and get into the burner. If you've only used it a dozen times or less this is highly unlikely.