According to them it is a Shawnee Indian legend which goes back to the 1700's of a hairy creature with extreme speed and strength which roams the woods of the tri state.
However until this show spoke about the Dustman I have never heard word one about it and I spent plenty of time camping in the woods in Washington County as a youth and have plenty of customers which takes me all over Washington county and its back roads at night and I have never ever heard any one talk about the Dustman. With all the exploration going on you think the gas well drillers would be talking about it as well and same thing no ones ever heard the legend I ever spoke to.
When you do research on the Dustman there is very little reference to it outside of the shows episode so once again it looks like a made up name for realty TV .
Yes the Shawnee do talk of the Big Foot creature in their legends but not of the dustman .
and the few recorded sightings in washington county do not use the name dustman
So while Big foot may be on the loose in Washington County he is no where near as active as neighboring Fayette County which has much denser woods .