Works for me
I have also used the electrical Relief Band on many of my single handed crossings of Lake Huron. Never once got sick while using one, but I can't be truly sure if it worked since I don't easly get sick anyway, and mostly used it because we had it (I bought it for my wife, who hated the electrical charges).
It does have a significant benefit for singlehanders, since the strength of the charges, while set on high (#5) is so uncomfortable that there is no way I was going to fall asleep on watch, even after 29 hours at the helm. Using it isn't a no-brainer, however, in that I found that any activity (sail change, trimming a sail) could dislodge the band from the proper point on my wrist, and I was always having to reposition it. Still I recommend it.