Kevin rubbing alcohol is fine to use.
DOnt worry, I have done mine with it, and they clean them great. I only had to soak for a half an hour though. I found a good way is to use peroxide. Fill ur atomizer with it, connect it to the battery, tape the outside after connection, so nothign leaks out, and then do a good burn with it, for about 15 to 20 seconds. works nicely.
after that, rinse it off pretty darn good with some water, dry it out with a hairdryer, or just air dry them for a day. Prime them with a drop or two, and wrap em up.
Also, after every nite of use, disconnect ur cartridge form ur atomizer, and let ur atomzeir drain out, just set it upright. it helps drain the excess juice out, that clogs it up. Always give it a good blow no and again, too.