[TheForge] electrolysis

[CGRAF]

Don't over think it.
Dilute muriatic in a  small open container set outside the door.
When it is done bubbling wait a minute or to and dump the whole shebang 
into a 5 gal pail of water. Pour it out on the driveway and retrieve the 
washers.

Assuming that you are starting out with a baby food sized container of 
the acid and washers the whole solution will be weaker than lemonade by 
a large margin, there is not enough zinc there to pose any kind of hazard.
I doubt you would even clean any dirt of the cement drive. Even if you 
did that is one of the things they sell the muriatic for in the Big Box.

Mike Graf