We've been salting them for years now. We just keep them in a zip-loc bag and bring a little lunch size cooler filled with ice when we fish. We've never had a problem re-freezing because if you use enough salt, they don't really freeze solid anyway.

I'm going to try the alcohol method though. That will keep the salt off of my reels. I have one reel that has been damaged due to the salt. The chrome was eaten right off the handle!