I could only go by my experience as a grunt - we didn't carry telephone equiment - just our PRC-25's - and I had that honor. The worst that could do is break a toe.
I can't see a need for wired telephone equipment on a swift boat either.
Hmmm... come to think of it, the firing generator for a claymore COULD (maybe) give some kind of shock, but I always found the actual claymore to be much more effective.
Wasn't one of Kerry's Purple Hearts for taking a claymore blast all by himself, saving his crew? I think it was on his web site.