When you need a DOOMcano, there’s no real substitute. And they’re not just selling these things on the street-corner. Nope, friend, you’ve got to get the hackerspace together and build your own.
For a fundraiser, and we suspect for the fun of it, the folks at LVL1 in Louisville, KY built a metal case with four (4!) flame-thrower jets. The idea is that you donate, and they’ll burn stuff for you.
Or you could build your own, following their detailed build log. LVL1 earns clever points for the use of 3D printer nozzles as gas jets, and for the laser-cut boxes that hold spray-cans of combustible fluid with servos to depress the buttons. It’s Rube-Goldbergy, but it works. Battery-powered grill igniters provide the spark, and an Arduino provides the control.