Joshua Putnam wrote:
Actually, "Whink" rust stain remover, usually found either in the
laundry aisle or in the bathroom cleaners section, is hydrofluoric
acid in a plastic squeeze bottle. Strong enough concentration to
etch many porcelain fixtures, but it does remove rust stains quite
well. Just avoid those nasty HF burns....

It's not quite that nice. Google on "hydrofluoric acid amputate" or
"hydrofluoric acid multi organ failure".

--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.