One of the things I do is keep whatever written material I'm working on stashed on iCloud and not on my local machines, so it's available but not actually on my devices.
Be sure you're logged out of iCloud when you pass through customs. While you're logged in, all your iCloud documents are mirrored in ~/Library/"Mobile Documents".
(I'm not sure how soon, or even if, this folder is emptied after you log out. It wouldn't hurt to peek.)
