I used them and am probably on the old thread!
They are not going to solve the root of the problem of sore nipples (latch issues, tongue tie, etc) but they might help relieve the actual trauma. Which would only re-occur if you hadn't sorted the actual issue IYSWIM.
I used them because I had a deep crack that wouldn't heal due to the presence of thrush. My rubbish latch had at last improved (due to baby growing, really) and the crack just wouldn't heal up because of the thrush.
Being highly suspicious of the whole silver thing (and broke after forking out for a million alternative thrush treatments to take alongside the fluconazole prescribed to me) I taped a silver ring onto the crack with micropore tape to see if it had any effect! I was amazed, but the ring was going to potentially cause blocked duct issues (dumb idea really!) so I bought the silverettes. They were half price when I bought them.
The crack just got better and better and within about a week had finally gone. I had had it for ages, weeks and weeks. Brilliant.
So for me, they worked, but like I said before, the initial cause had been sorted out.
HTH and best of luck with bf. I never thought EVER that I would feed pain free and although it took forever, with the help on MN, Kellymom website and a lovely real life breast feeding counsellor and weekly support group I am still feeding my son and he's neary 2!