it takes a long time even with really bad CS. i wouldnt worry about bluing with a good home made or utopia either one.
the only herx i ever got with silver was sleeping. it made me dead tired and i slept for days at a time. it was a relief for me but i could no longer work as it was anyway.
i took tons of high ppm YELLOW CS. i have no doubt about its safety. my experience leads me to believe that the right dosage is as much as it takes to work. your answer is no doubt in that ballpark.