If you're worried about effectiveness and the stomach, you can hold the CS under your tongue for a minimum of 1 min to improve absorption before swallowing it. I can confirm this works btw. as I successively treated my condition by holding and spitting out 2oz of ionic silver four times per day.
As for the percentage I use, I cannot say. Though making it is really simple:
I start by heating my distilled water just under boiling(until bubbles start to form). I then start the process by turning on electricity and let things run just short of turning yellow and I'm done. I usually make 2L at a time, and so I timed how long it took for the solution to turn yellow and now make it just short of that.
NB. when you add heat to the process, the electrodes forms very little oxide(hardly any). And if your batch is small enough, you can usually finish without ever having to ever clean them in the process.