It works for sure, but I bet his plastic hood doesn't look pretty now. I would consider that approach for a small grass fire if it threatened my house and I had nothing else otherwise just let it burn. It wont hurt the grass and it will come back faster in the spring than unburned areas. He could likely have done the same thing without putting his tractor in the flame buy just running the mower along the edge of the flame as they do cut past the wheels in most cases. The mower cut and blast of air might do the same thing. Either way, if it was threatening his home, sacrificing his $2-3K lawnmower is better than losing his house and likely only thing hurt if anything would be the plastic shell for hood and front bumper.