My Lush solid shampoo bar just made it through KOA security just fine. (At least the initial screening, haven't gone through gateside yet. And, I wasn't selected for secondary.) I can't see how they would honestly tell the difference in xray between a tin of gel and a tin with my shampoo bar in it. Especially if you introduced some bubbles into the gel to make it look a bit 'rough' like the bar.