Are weed burners effective?

I tried one, but as i''m in my 80s I found it difficult to use, I have no muscle strength in my arms so it strained my back holding it in front of me. I should imagine a young fit person would find them brilliant.
(Try leaning slightly forwards with a brush in your stretched arms for a few minutes, and it gives you some idea how your own body reacts.)

They are can be very satisfying! Excellent for getting the bonfire going as well but weeding properly is more efficient in my opinion.