I imagine it's a weed wand rather than a flame thrower, a far less aggressive beast. I use one too, also because it saves my back at times (expensive to use, though. Occasionally Lidl sells the cartridges far cheaper than anyone else so I stock up). They're quite good for making the straight edge of my grass against the gravel drive. You have to be careful not to burn your precious plants as well as the weeds. Once the cartridge is around half-used, it loses its oomph as the remaining gas gets very cold due to expansion. You have to give it a rest for half an hour. The weeds always come back. It's a stopgap really, and all that carbon dioxide released...