I am not at all comfortable with a 3600 PPM silver product, no matter what their website has to say. The true benchmark for colloidal silver is particle size anyway, and it could be that their particle sizes are large enough that there is really not that much difference between the 20 PPM most of us here recommend. I note on their website that, while they quoted an EPA report that said 90-99% of ingested silver is eliminated from the body, I would note that it was NOT Nutrasilver which was tested.
Even if that measurement applied to Nutra silver, 10% retention of 3600 PPM silver would be a huge difference over 10% retention of 20 PPM, since that would work out to 360 PPM retention of silver for Nutrasilver versus 2 PPM retention of the recommended 20 PPM. I also noted that, while they bragged Nutrasilver's success with Morgellons, they reported that
"Many Morgellons victims report that upon ceasing use of NutraSilver®, their symptoms begin to return within a few weeks."
That sounds to me like it would require long term use to be successful for at least that condition and possibly others - and, given the huge PPM of their product, that would concern me. People turning blue from silver are very rare. Usually it takes a very high PPM silver, likely large particle silver at that, taken over a long period in quantity and likely some other contamination, such as salt and other chemicals. In my estimation, Nutrasilver qualifies as a high PPM silver.
One other note: I never heard of anyone having to "work their way up" to a higher doseage of silver.