There is a company in Ashland, Ky called Expro. The travel throughout the US and even the world cleaning very large boilers and smokestacks with explosives on the end of broom sticks and shooting the "clinkers" off with shotguns and 00 buck shot.
Comapny is Expro located in the Ashland Regional Airport (the one Jeff Foxworthy yalked about on one of his dvds). Their phone is 606-834-9402. The company is run by Brad McGuinnis. I worked at the airport as night manager and had to get their jet out all of the time. It is a massively dirty and also dangerous job. There are only like 2 other companies in the US that even do it.