These things have been around for at least 30 years or more. They never did catch on in the construction world. I used one once and they are really slick, no slag or metal gobs, just ash. One problem was that in spite of the all the safety testing and code certifications, fire departments did not want that cylinder of gasoline in a building and Safety Police then banned them. They were even certified by the US Coast Guard for use aboard ships. They are pretty expensive as they do not sell that many.
Ron