LOL... if the full body scanners can "see" your package, they can certainly see that it's encased and locked up tight. Just because no one pointed at you and commented or laughed, doesn't mean they didn't see...

I can almost certainly guarantee if the angle of viewing makes it look "clockworky" or mechanical, they may well pull you out of line for a closer look.

They can detect a full catheter bag with these things. Better keep those liquids under the requisite 311 rule before going through TSA.