I've done that for years; it is easy, cheap, and portable.  CS made  that way 
is easily destroyed by light, I understand, so store it in a dark  place.  
Try to consume it immediately, for optimum potency; the silver  tends to settle 
out over time when made by this method.  
 
Also, if you make CS this way, be sure and stand nearby until the process  is 
complete.  Depending on the hardness of the water, the silver may be  ready 
in 30 seconds, to 3 minutes.  If you take a phone call while making  your 
silver, you could return to find black muddy water!
 
Jill