>Many of us don't use FeCl in large quantity
I haven't used it for at least two years. It's just too messy and the
color is such that visually following the etching process is difficult
unless you remove the board from it. Using a timer was helpful but the
time increased for each reuse.
>Use as anti-weed is not stupid at all!
Careful where you use it, that stuff seems to have a knack for showing
up where and when least expected. Some corollary of Murphy's law says
that it will rain, get on the soles of somebody's shoes then get
trekked all over the place. Worse still if you have a pet like a dog.