Yeah, I'm not overly impressed with the blue guns but they would be a lot easier to get through customs than an airsoft gun...it just looks and feels too real to the average customs guy.
I was just reading a bit of Steve Anderson's latest book and he mentioned that it can actually hurt your shooting if you do nothing but dry fire so maybe I'm taking the wrong approach. Maybe it's just a matter of doing some visualization, movement drills, etc. while I'm at work and then doubling up on the dry fire/live fire when I'm home.