I've used PBW on swing-top bottles and they're fine. You should be replacing the rubber gaskets after a half dozen uses or so anyway, but the cleaners won't ruin them after one clean. Hope that helps.
Here's something that should help: http://www.midwestsupplies.com/diffe...-cleaners.html
OneStep & Easy Clean are essentially the same product under different brand names.
There's a chart out there somewhere that compares all the available cleaners, but I have only seen it on paper... I think it was in a recent issue of Zymurgy, though I can't find it by searching their site. If you get their magazine, I think it was in the past 2-3 issues. (or was it BYO? Curse this memory of mine!)