The present invention discloses an apparatus and method for cleaning an exhaust conduit that has chemical substances deposited on its inside wall by utilizing a shaft that has a plurality of scraping elements mounted thereto capable of making vertically or radially oscillating motions inside the exhaust conduit such that the chemical substances can be dislodged from the inside wall and the exhaust conduit can be effectively cleaned. The apparatus may optionally include fluid nozzles provided in the shaft for dispensing a cleaning fluid during the cleaning process to further enhance the efficiency. The apparatus may further include a vacuum device for effectively removing the debris dislodged from the inside wall during such cleaning process.