Should I make my own CS or buy CS with a higher concentration?

I found the CS sold in store have a higher ppm, it can be 500ppm or 2000ppm. Also, I understand the effectiveness of CS is by the silver particle size as well as concentration. In Dr. Clark's CS, the instruction only mentioned making up to 100ppm by microwaving. So if the concentration is not high as those sold, should I just bought in store for Herpes 2? Thanks.