We use what weāre told to use and what is around us constantly. Same as you. I think any complaints you have should be directed towards the government.
I have no idea how legit that light and battery are but there are a lot of products that can be made and sold dirt cheap if you donāt care about the quality or brand. Here is a pack of penlights (no batteries though) for about $18:
I use a propane torch on graveled areas instead of herbicides to avoid chemicals.
I only singe the weeds very quickly with the torch and that is enough to kill the exposed foliage from the interior moisture in the weed bursting the plant's cells.
The weeds do grow back since the roots do not heat up enough to be killed but after a few times getting the foliage's attention with the torch about once a week the weeds do seem to eventually die.
It seems to me like the actual force of the jet coming from a propane torch blows a lot of the heat out and away when you have it close to something. Iāve never had good luck with using them for weeds either.
Personally Iām going to keep using chemical weed killers. The studies on them, litigation that followed, and media portrayal of both arenāt really painting the whole picture: