Airline security is a placebo.
There is no way to detect an internal explosive using conventional means. A determined bomber could implant boobie bombs (14 lbs of explosive if the person is willing to die)
the gastro intestinal tract works pretty good for smuggling. Then there is still the old jump the fence at the right moment and you can access a plane with anything you want with out being inspected.
Blades made from glass/ceramic as well as hard plastics are undetectable with current lax checking proceedures. Heck My guess is that even their sniffing equipment could not detect an altered shaving cream can with a false charge of foam for security guards to check.
a bar of soap probably could be smuggled in with out effort undetected . Hermetically seal a bar of c/4 inside of a bar of soap. There is no effective way to avoid it AFAIAC.
I would love to have a job as a security analyst where I check the checkers.